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 A081556 #13 Jun 09 2018 13:43:51 %S A081556 1,2,5,4,8,6,11,8,14,10,17,12,20,14,23,16,26,18,29,20,32,22,32,24,38, %T A081556 26,41,28,44,30,47,32,50,34,53,36,56,38,59,40,62,42,65,44,68,46,71,48, %U A081556 74,50,77,52,80,54,83,56,86,58,89,60,92,62,95,64,98,66,101,68,104,70 %N A081556 Next-to-last term in n-th row of A080504. %C A081556 If n is odd, a(n) = n-1. If n is even, n-1 <= a(n) <= 3n/2-1. For even n up to 100, a(n) = 3n/2-1 unless n = 2 or 24; are there other exceptions? - _Dean Hickerson_, Mar 21 2003 %e A081556 a(24)=32 since the 24th row of A080504 can be exhibited as: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 32, y with y = 3^15*5^20*7^21*11^22*13^23*17^23*19^23. %Y A081556 Cf. A080504, A080505, A080506, A080507. %K A081556 nonn %O A081556 2,2 %A A081556 _Dean Hickerson_, Mar 21 2003