Search: id:A007949 Results 1-1 of 1 results found. %I A007949 %S A007949 0,0,1,0,0,1,0,0,2,0,0,1,0,0,1,0,0,2,0,0,1,0,0,1,0,0,3,0,0,1,0,0,1,0,0, %T A007949 2,0,0,1,0,0,1,0,0,2,0,0,1,0,0,1,0,0,3,0,0,1,0,0,1,0,0,2,0,0,1,0,0,1,0, %U A007949 0,2,0,0,1,0,0,1,0,0,4,0,0,1,0,0,1,0,0,2,0,0,1,0,0,1,0,0,2,0,0,1,0,0,1 %N A007949 Greatest k such that 3^k divides n. Or, 3-adic valuation of n. %C A007949 a(n) mod 2 = 1 - A014578(n). [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Oct 04 2008] %D A007949 K. Atanassov, On the 61-st, 62-nd and the 63-rd Smarandache Problems, Notes on Number Theory and Discrete Mathematics, Sophia, Bulgaria, Vol. 4 (1998), No. 4, 175-182. %D A007949 K. Atanassov, On Some of Smarandache's Problems, American Research Press, 1999, 16-21. %D A007949 F. Q. Gouvea, p-Adic Numbers, Springer-Verlag, 1993; see p. 23. %D A007949 F. Smarandache, Only Problems, not Solutions!, Xiquan Publ., Phoenix-Chicago, 1993. %D A007949 M. Vassilev-Missana and K. Atanassov, Some Representations related to n!, Notes on Number Theory and Discrete Mathematics, Vol. 4 (1998), No. 4, 148-153. %H A007949 T. D. Noe, Table of n, a(n) for n=1..1000 %H A007949 K. Atanassov, On Some of Smarandache's Problems %H A007949 M. L. Perez et al., eds., Smarandache Notions Journal %H A007949 F. Smarandache, Only Problems, Not Solutions!. %F A007949 a(n) = if n > 0 modulo 3 then 0 else 1 + a(n/3). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Aug 12 2001 %F A007949 a(n)=A051064(n)-1. G.f.: Sum(k>=1, x^3^k/(1-x^3^k)))). - Ralf Stephan (ralf(AT)ark.in-berlin.de), Apr 12 2002 %F A007949 Fixed point of the morphism : 0 -> 001; 1 -> 002; 2 -> 003; 3 -> 004; 4 -> 005; etc...; starting from a(1) = 0. - DELEHAM Philippe (kolotoko(AT)wanadoo.fr), Mar 29 2004 %F A007949 Totally additive with a(p) = 1 if p = 3, 0 otherwise. %p A007949 A007949 := proc(n) option remember; if n mod 3 > 0 then 0 else A007949(n/ 3)+1; fi; end; %t A007949 p=3; Array[ If[ Mod[ #, p ]==0, Select[ FactorInteger[ # ], Function[ q, q[ [ 1 ] ]==p ], 1 ][ [ 1, 2 ] ], 0 ]&, 81 ] %t A007949 Nest[ Function[ l, {Flatten[(l /. {0 -> {0, 0, 1}, 1 -> {0, 0, 2}, 2 -> {0, 0, 3}, 3 -> {0, 0, 4}}) ]}], {0}, 5] (from Robert G. Wilson v Mar 03 2005) %o A007949 (PARI) a(n)=valuation(n,3) %Y A007949 Partial sums give A054861. Cf. A080278, A001511. %Y A007949 Cf. A122841, A007814, A112765. %Y A007949 Sequence in context: A016380 A015692 A016232 this_sequence A078595 A078128 A112607 %Y A007949 Adjacent sequences: A007946 A007947 A007948 this_sequence A007950 A007951 A007952 %K A007949 nonn,easy %O A007949 1,9 %A A007949 R. Muller Search completed in 0.002 seconds