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

0,2

Links

Table of n, a(n) for n=0..13.

Prog

(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])

Crossrefs

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

Sequence in context: A014479 A013992 A279156 * A111812 A138433 A242597

Adjacent sequences: A129100 A129101 A129102 * A129104 A129105 A129106

Keyword

nonn

Author

Paul D. Hanna, Mar 29 2007

Status

approved