Search: id:A001021 Results 1-1 of 1 results found. %I A001021 M4869 N2084 %S A001021 1,12,144,1728,20736,248832,2985984,35831808,429981696,5159780352, %T A001021 61917364224,743008370688,8916100448256,106993205379072,1283918464548864, %U A001021 15407021574586368,184884258895036416,2218611106740436992 %N A001021 Powers of 12. %C A001021 Central terms of the triangle in A100851. - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Mar 04 2006 %C A001021 Number of n-permutations of 13 objects: n, o, p, q, r, s, t, u, v, w, z, x, y with repetition allowed and containing no u's, (u-free). Permutations with repetitions! If n=0 then 1 >>12^0=1 "". (no u's.) If n=1 then 12 >>12^1=12, >> n, o, p, q, r, s, t, v, w, z, x, y. (no u's.) etc. [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 29 2009] %D A001021 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). %D A001021 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A001021 T. D. Noe, Table of n, a(n) for n=0..100 %H A001021 P. J. Cameron, Sequences realized by oligomorphic permutation groups, J. Integ. Seqs. Vol. 3 (2000), #00.1.5. %H A001021 INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 276 %H A001021 Tanya Khovanova, Recursive Sequences %H A001021 S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992. %H A001021 S. Plouffe, 1031 Generating Functions and Conjectures, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 1992. %H A001021 Y. Puri and T. Ward, Arithmetic and growth of periodic orbits, J. Integer Seqs., Vol. 4 (2001), #01.2.1. %F A001021 G.f.: 1/(1-12x), e.g.f.: exp(12x) %F A001021 a(n) = 12*a(n-1). [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 27 2009] %p A001021 A001021:=-1/(-1+12*z); [S. Plouffe in his 1992 dissertation.] %o A001021 (Other) sage: [lucas_number1(n,12,0) for n in xrange(1, 19)]# [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 27 2009] %Y A001021 a(n) = A159991(n)/A000351(n). [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 02 2009] %Y A001021 Sequence in context: A163448 A004191 A051051 this_sequence A159490 A000468 A076728 %Y A001021 Adjacent sequences: A001018 A001019 A001020 this_sequence A001022 A001023 A001024 %K A001021 nonn,easy %O A001021 0,2 %A A001021 N. J. A. Sloane (njas(AT)research.att.com). Search completed in 0.002 seconds