Search: id:A004736 Results 1-1 of 1 results found. %I A004736 %S A004736 1,2,1,3,2,1,4,3,2,1,5,4,3,2,1,6,5,4,3,2,1,7,6,5,4,3,2,1,8,7,6,5,4,3,2, %T A004736 1,9,8,7,6,5,4,3,2,1,10,9,8,7,6,5,4,3,2,1,11,10,9,8,7,6,5,4,3,2,1,12, %U A004736 11,10,9,8,7,6,5,4,3,2,1,13,12,11,10,9,8,7,6,5,4,3,2,1,14,13,12,11,10, 9 %N A004736 Triangle T(n,k) = n-k, n >= 1, 0<=k= 1, k >= 1) by antidiagonals upwards: n -> T(t1(n), t2(n)). - Michael Somos, Aug 23, 2002 %D A004736 C. Kimberling, "Numeration systems and fractal sequences," Acta Arithmetica 73 (1995) 103-117. %D A004736 F. Smarandache, "Collected Papers", Vol. II, Tempus Publ. Hse., Bucharest, 1996; F. Smarandache, "Numerical Sequences", University of Craiova, 1975; [ See Arizona State University, Special Collection, Tempe, AZ, USA ]. %D A004736 F. Smarandache, Sequences of Numbers Involved in Unsolved Problems, Hexis, Phoenix, 2006. %D A004736 H. S. M. Coxeter, Regular Polytopes, 3rd ed., Dover, NY, 1973, pp 159-162 [From Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Mar 25 2009] %H A004736 C. Kimberling, Fractal sequences %H A004736 M. L. Perez et al., eds., Smarandache Notions Journal %H A004736 F. Smarandache, Collected Papers, Vol. II %H A004736 F. Smarandache, Sequences of Numbers Involved in Unsolved Problems. %H A004736 M. Somos, Sequences used for indexing triangular or square arrays %H A004736 Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics. %F A004736 a(n) = (2 - 2 n + round(SQRT(2 n)) + round(SQRT(2 n))^2)/2. E.g. a(47) = 9. - Brian Tenneson (phoenix(AT)alephnulldimension.net), Oct 11 2003 %F A004736 G.f.: 1 / [(1-x)^2 * (1-xy) ]. - R. Stephan, Jan 23 2005 %F A004736 Contribution from Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Mar 25 2009: (Start) %F A004736 Recursion: %F A004736 e(n,k) = (e(n - 1, k)*e(n, k - 1) + 1)/e(n - 1, k - 1); (End) %e A004736 1; 2,1; 3,2,1; 4,3,2,1; 5,4,3,2,1; ... %e A004736 Contribution from Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Mar 25 2009: (Start) %e A004736 {1}, %e A004736 {2, 1}, %e A004736 {3, 2, 1}, %e A004736 {4, 3, 2, 1}, %e A004736 {5, 4, 3, 2, 1}, %e A004736 {6, 5, 4, 3, 2, 1}, %e A004736 {7, 6, 5, 4, 3, 2, 1}, %e A004736 {8, 7, 6, 5, 4, 3, 2, 1}, %e A004736 {9, 8, 7, 6, 5, 4, 3, 2, 1}, %e A004736 {10, 9, 8, 7, 6, 5, 4, 3, 2, 1} (End) %p A004736 (Excel cell formula) =if(row()>=column();row()-column()+1;"") [From Mats Granvik (mats.granvik(AT)abo.fi), Jan 19 2009] %t A004736 Flatten[ Table[ Reverse[ Range[n]], {n, 12}]] (from Robert G. Wilson v Apr 27 2004) %t A004736 Contribution from Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Mar 25 2009: (Start) %t A004736 Clear[e, n, k]; %t A004736 e[n_, 0] := n; %t A004736 e[n_, k_] := 0 /; k >= n; %t A004736 e[n_, k_] := (e[n - 1, k]*e[n, k - 1] + 1)/e[n - 1, k - 1]; %t A004736 Table[Table[e[n, k], {k, 0, n - 1}], {n, 1, 10}]; %t A004736 Flatten[%] (End) %o A004736 (PARI) a(n)=1+binomial(1+floor(1/2+sqrt(2*n)),2)-n %o A004736 (PARI) t1(n)=binomial(floor(3/2+sqrt(2*n)),2)-n+1 /* A004736 */ %o A004736 (PARI) t2(n)=n-binomial(floor(1/2+sqrt(2*n)),2) /* A002260 */ %Y A004736 a(n+1)=1+A025581(n). Cf. A002262, A025581, A003056. %Y A004736 Ordinal transform of A002260. %Y A004736 Sequence in context: A141671 A088643 A102482 this_sequence A167288 A167289 A023122 %Y A004736 Adjacent sequences: A004733 A004734 A004735 this_sequence A004737 A004738 A004739 %K A004736 nonn,easy,tabl,nice %O A004736 1,2 %A A004736 R. Muller Search completed in 0.002 seconds