cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A085643 Refines sequence A078812 using permutations and products of exponents on least prime signatures.

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%I A085643 #3 Mar 31 2012 13:23:37
%S A085643 1,2,1,3,4,1,4,6,4,6,1,5,8,12,9,12,8,1,6,10,16,9,12,36,8,12,24,10,1,7,
%T A085643 12,20,24,15,48,36,27,16,72,32,15,40,12,1,8,14,24,30,16,18,60,48,72,
%U A085643 54,20,96,144,54,16,20,120,80,18,60,14,1
%N A085643 Refines sequence A078812 using permutations and products of exponents on least prime signatures.
%C A085643 The shape sequence for this table is A000041. Row sums in the example are A000079, A006906 and A001906.
%e A085643 When the signatures (A025487) are listed in A036035 order the number of permutations of the exponents begin
%e A085643 1, 1 1, 1 2 1, 1 2 1 3 1, 1 2 2 3 3 4 1, ... b(n) and the products begin
%e A085643 1, 2 1, 3 2 1, 4 3 4 2 1, 5 4 6 3 4 2 1, ... c(n) thus we can write
%e A085643 1, 2 1, 3 4 1, 4 6 4 6 1, 5 8 12 9 12 8 1, ... a(n) = b(n)*c(n)
%Y A085643 Cf. A078812.
%K A085643 nonn,tabf
%O A085643 1,2
%A A085643 _Alford Arnold_, Aug 15 2003