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 A125794 #8 Jun 14 2017 00:16:28 %S A125794 1,5,25,165,1625,25509,664665,29559717,2290267225,314039061413, %T A125794 77160820913241,34317392762489765,27859502236825957465, %U A125794 41575811106337540656037,114746581654195790543205465,588765612737696531880325270437,5642056933026209681424588087899225 %N A125794 Column 4 of table A125790; also equals row sums of matrix power A078121^4. %C A125794 Triangle A078121 shifts left one column under matrix square and is related to partitions into powers of 2. %H A125794 Alois P. Heinz, <a href="/A125794/b125794.txt">Table of n, a(n) for n = 0..50</a> %o A125794 (PARI) a(n)=local(p=4,q=2,A=Mat(1), B); for(m=1, n+1, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i || j==1, B[i, j]=1, B[i, j]=(A^q)[i-1, j-1]); )); A=B); return(sum(c=0,n,(A^p)[n+1,c+1])) %Y A125794 Cf. A125790, A078121; columns: A002577, A125792, A125793, A125795, A125796; diagonals: A125797, A125798. %Y A125794 A diagonal of A152977. %K A125794 nonn %O A125794 0,2 %A A125794 _Paul D. Hanna_, Dec 10 2006