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 A093057 #4 Mar 31 2012 10:29:04 %S A093057 0,0,1,0,0,2,0,1,0,3,0,0,0,0,4,0,1,2,1,0,5,0,0,0,0,0,0,6,0,1,0,3,0,1, %T A093057 0,7,0,0,2,0,0,2,0,0,8,0,1,0,1,4,1,0,1,0,9,0,0,0,0,0,0,0,0,0,0,10,0,1, %U A093057 2,3,0,5,0,3,2,1,0,11,0,0,0,0,0,0,0,0,0,0,0,0,12,0,1,0,1,0,1,6,1,0,1,0,1,0 %N A093057 Triangle T(j,k) read by rows, where T(j,k) = number of matrix elements remaining at fixed position in the in-situ transposition of a rectangular j X k matrix (singleton cycles). %C A093057 Elements (1,1) and (j,k) which always remain at their old position are not counted. See A093055 for details of storage, another example, references and links. %F A093057 T(j, k)=gcd(j-1, k-1)-1. %e A093057 a(8)=T(3,5)=1 because there is one fixed element at position 8 in the transposition from %e A093057 (1 2 3 4 5)(6 7 8 9 10)(11 12 13 14 15) -> %e A093057 (1 6 11)(2 7 12)(3 8 13)(4 9 14)(5 10 15). The fixed first and last elements 1 and 15 are not counted. %Y A093057 Cf. A093055 number of non-singleton cycles, A093056 length of longest cycle, A050873 GCD(u, v). %K A093057 nonn,tabl %O A093057 1,6 %A A093057 _Hugo Pfoertner_, Mar 22 2004