A125793 Column 3 of table A125790; also equals row sums of matrix power A078121^3.

1, 4, 16, 84, 656, 8148, 167568, 5866452, 356855440, 38315189204, 7352635371152, 2547660633170900, 1607532367023451792, 1860491404939092059092, 3974085151281967171382928, 15751822048486986712162264020

Offset: 0

Author

Paul D. Hanna, Dec 10 2006

Keywords

• nonn

Comments

Triangle A078121 shifts left one column under matrix square and is related to partitions into powers of 2.

Crossrefs

Cf. A125790, A078121; columns: A002577, A125792, A125794, A125795, A125796; diagonals: A125797, A125798.

Programs

PARI

a(n)=local(p=3,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]))