A098606 Sum of all matrix elements M(i,j) = (i^2)/(i+j).

0, 1, 76, 7032, 889920, 151876800, 33953713920, 9671337446400, 3426840152064000, 1480226878835712000, 766252171508060160000, 468506511112577236992000, 334155981137427201392640000

Offset

0,3

Links

Table of n, a(n) for n=0..12.

Formula

a(n) = (2*n)!*Sum[Sum[(i^2)/(i+j), {i, 1, n}], {j, 1, n}]

Mathematica

Table[(2*n)!*Sum[Sum[(i^2)/(i+j), {i, 1, n}], {j, 1, n}], {n, 0, 15}]

Crossrefs

Sequence in context: A198476 A234778 A139671 * A093276 A184290 A093238

Adjacent sequences: A098603 A098604 A098605 * A098607 A098608 A098609

Keyword

nonn

Author

Alexander Adamchuk, Oct 26 2004

Status

approved