Search: id:A047999 Results 1-1 of 1 results found. %I A047999 %S A047999 1,1,1,1,0,1,1,1,1,1,1,0,0,0,1,1,1,0,0,1,1,1,0,1,0,1,0,1,1,1,1, %T A047999 1,1,1,1,1,1,0,0,0,0,0,0,0,1,1,1,0,0,0,0,0,0,1,1,1,0,1,0,0,0,0, %U A047999 0,1,0,1,1,1,1,1,0,0,0,0,1,1,1,1,1,0,0,0,1,0,0,0,1,0,0,0,1,1,1 %N A047999 Sierpinski's triangle (or gasket): triangle, read by rows, formed by reading Pascal's triangle mod 2. %C A047999 Also triangle giving successive states of cellular automaton generated by "Rule 60" and "Rule 102". - Hans Havermann (pxp(AT)rogers.com), May 26 2002 %C A047999 Also triangle formed by reading triangle of Eulerian numbers (A08292) mod 2. - DELEHAM Philippe (kolotoko(AT)wanadoo.fr), Oct 02 2003 %C A047999 Self-inverse when regarded as an infinite lower triangular matrix over GF(2). %C A047999 Start with [1], repeatedly apply the map 0 -> [00/00], 1 -> [10/11] [Allouche and Berthe] %C A047999 Also triangle formed by reading triangles A011117, A028338, A039757, A059438, A085881, A086646, A086872, A087903, A0104219 mod 2 . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Jun 18 2005 %C A047999 J. H. Conway writes (in Math Forum): at least the first 31 rows give odd-sided constructible polygons (sides 1, 3, 5, 15,17 ... see A001317). The 1's form a Sierpinski sieve. - M. Dauchez (mdzzdm(AT)yahoo.fr), Sep 19 2005 %C A047999 When regarded as an infinite lower triangular matrix, its inverse is a (-1,0,1)-matrix with zeros undisturbed and the nonzero entries in every column form the Prouhet-Thue-Morse sequence (1,-1,-1,1,-1, 1,1,-1,...) A010060 (up to relabeling). - David Callan (callan(AT)stat.wisc.edu), Oct 27 2006 %C A047999 Triangle read by rows: antidiagonals of an array formed by successive iterates of running sums mod 2, beginning with (1, 1, 1,...). - Gary W. Adamson (qntmpkt(AT)yahoo.com), Jul 10 2008 %D A047999 R. K. Guy, The strong law of small numbers. Amer. Math. Monthly 95 (1988), no. 8, 697-712. %D A047999 Y. Moshe, The distribution of elements in automatic double sequences, Discr. Math., 297 (2005), 91-103. %D A047999 S. Wolfram, A New Kind of Science, Wolfram Media, 2002; Chapter 3. %H A047999 T. D. Noe, Rows n=0..50 of triangle, flattened %H A047999 J.-P. Allouche and V. Berthe, Triangle de Pascal, complexite et automates. %H A047999 J. Baer, Explore patterns in Pascal's Triangle %H A047999 A. Bogomolny, Dot Patterns and Sierpinski Gasket %H A047999 S. Butkevich, Pascal Triangle Applet %H A047999 B. Cherowitzo, Pascal's Triangle using Clock Arithmetic, Part I %H A047999 B. Cherowitzo, Pascal's Triangle using Clock Arithmetic, Part II %H A047999 A. Granville, Pascal's Triangle Interface %H A047999 I. Kobayashi et al., Pascal's Triangle %H A047999 Dr. Math, Regular polygon formulas>Regular polygon formulas %H A047999 National Curve Bank, Sierpinski Triangles %H A047999 F. Richman, Pascal's triangle modulo n %H A047999 F. Richman, Pascal's triangle modulo n %H A047999 Eric Weisstein's World of Mathematics, Sierpinski Sieve %H A047999 Eric Weisstein's World of Mathematics, Rule 60 %H A047999 Eric Weisstein's World of Mathematics, Rule 102 %H A047999 Index entries for sequences related to cellular automata %H A047999 Index entries for triangles and arrays related to Pascal's triangle %H A047999 Index entries for sequences generated by sieves %F A047999 Sum_{k>=0} T(n, k) = A001316(n) = 2^A000120(n). %e A047999 Triangle begins: %e A047999 .1, %e A047999 .1,1, %e A047999 .1,0,1, %e A047999 .1,1,1,1, %e A047999 .1,0,0,0,1, %e A047999 .1,1,0,0,1,1, %e A047999 .1,0,1,0,1,0,1, %e A047999 .1,1,1,1,1,1,1,1, %e A047999 .1,0,0,0,0,0,0,0,1, %e A047999 .1,1,0,0,0,0,0,0,1,1, %e A047999 .1,0,1,0,0,0,0,0,1,0,1, %e A047999 .1,1,1,1,0,0,0,0,1,1,1,1, %e A047999 .1,0,0,0,1,0,0,0,1,0,0,0,1, %e A047999 .... %t A047999 Mod[ Flatten[ NestList[ Prepend[ #, 0] + Append[ #, 0] &, {1}, 13]], 2] (from Robert G. Wilson v May 26 2004) %o A047999 Contribution from Gerald McGarvey (gerald.mcgarvey(AT)comcast.net), Oct 10 2009: (Start) %o A047999 (PARI) \\ Recurrence for Pascal's triangle mod p, here p = 2. %o A047999 p = 2; s=13; T=matrix(s,s); T[1,1]=1; %o A047999 for(n=2,s, T[n,1]=1; for(k=2,n, T[n,k] = (T[n-1,k-1] + T[n-1,k])%p )); %o A047999 for(n=1,s,for(k=1,n,print1(T[n,k],", "))) (End) %Y A047999 Cf. A007318, A054431, A001317, A008292, A083093, A034931, A034930, A008975, A034932. %Y A047999 Sequence in context: A144093 A143200 A166282 this_sequence A054431 A164381 A106470 %Y A047999 Adjacent sequences: A047996 A047997 A047998 this_sequence A048000 A048001 A048002 %K A047999 nonn,tabl,easy,nice %O A047999 0,1 %A A047999 N. J. A. Sloane (njas(AT)research.att.com). %E A047999 Additional links from Lekraj Beedassy (blekraj(AT)yahoo.com), Jan 22 2004 Search completed in 0.002 seconds