A303001 a(n) = permanent of the n X n matrix with entries a(i, i) = i*(i+1)/2 and a(i, j) = 1 elsewhere.

1, 4, 30, 356, 6106, 142760, 4363848, 168986136, 8087082144, 468807362736, 32379640476000, 2627735592279600, 247610398718738640, 26815386224063189760, 3307855985755600598400, 461149884030679844958720, 72151124506962747825006720, 12590610689213961622942752000

Offset: 1

Author

Vaclav Kotesovec, Apr 17 2018

Keywords

• nonn

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 1..36

Crossrefs

Cf. A007840, A010791, A067550, A118714, A303000.

Programs

Mathematica

Table[Permanent[DiagonalMatrix[Table[i*(i+1)/2-1, {i, 1, n}]] + 1], {n, 1, 20}]

PARI

{a(n) = matpermanent(matrix(n, n, i, j, if(i==j, i*(i+1)/2, 1)))}
for(n=1, 20, print1(a(n), ", ")) \\ Vaclav Kotesovec, Dec 20 2018