A129103 Column 3 of triangle A129100; also equals column 0 of matrix power A129100^8.

1, 8, 72, 880, 16032, 461992, 21944520, 1770483408, 248136807776, 61460157645704, 27267123945408968, 21902527945097597616, 32134030755805852610720, 86739696410985770930422760

Offset: 0

Author

Paul D. Hanna, Mar 29 2007

Keywords

• nonn

Crossrefs

Cf. A129100 (triangle); A129092 (column 0), A129101 (column 1), A129102 (column 2).

Programs

PARI

a(n)=local(A=Mat(1),B);for(m=1,n+4,B=matrix(m,m);for(r=1,m,for(c=1,r, if(r==c || r==1 || r==2,B[r,c]=1,if(c==1,B[r,1]=sum(i=1,r-1,A[r-1,i]), B[r,c]=(A^(2^(c-1)))[r-c+1,1])); )); A=B); return(A[n+4,4])