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.
%I A243072 #18 Jun 21 2014 14:21:18 %S A243072 1,2,4,3,8,6,12,5,9,12,20,10,28,18,18,7,44,15,52,20,27,30,68,14,36,42, %T A243072 25,30,76,30,92,11,45,66,54,21,116,78,63,28,124,45,148,50,50,102,164, %U A243072 22,81,60,99,70,172,35,90,42,117,114,188,42,212,138,75,13,126 %N A243072 Second order Bulgarian solitaire operation on partition list A112798: a(1) = 1, a(n) = A000040(A001222(n)) * A242424(A064989(n)). %C A243072 The usual Bulgarian Solitaire operation (the "first order" version, cf. A242424) applied to an unordered integer partition means: subtract one from each part, and add a new part as large as there were parts in the old partition. %C A243072 The "Second Order Bulgarian Solitaire" operation means that after subtracting one from each part of the old partition (and discarding the parts that diminished to zero), we apply the (first order) Bulgarian operation to the remaining partition before adding a new part as large as there were parts in the original partition. %C A243072 In this context, where the parts of partitions are encoded with the indices of primes in the prime factorization of n (as in A112798), A064989(n) gives the remaining partition after one has been subtracted from each part; A242424 applies the first order Bulgarian operation to it; and multiplying with A000040(A001222(n)) adds a part as large as there originally were parts. %H A243072 Antti Karttunen, <a href="/A243072/b243072.txt">Table of n, a(n) for n = 1..8192</a> %F A243072 a(1) = 1, a(n) = A000040(A001222(n)) * A242424(A064989(n)) = A105560(n) * A242424(A064989(n)). %F A243072 a(n) = A241909(A243052(A241909(n))). %o A243072 (Scheme, with _Antti Karttunen_'s IntSeq-library) %o A243072 (definec (A243072 n) (if (<= n 1) n (* (A000040 (A001222 n)) (A242424 (A064989 n))))) %Y A243072 Row 2 of A243070. Differs from A122111 for the first time at n=7. %Y A243072 Cf. A242424, A243073, A112798, A105560, A000040, A001222, A064989, A243052, A241909. %K A243072 nonn %O A243072 1,2 %A A243072 _Antti Karttunen_, May 29 2014