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A098606
Sum of all matrix elements M(i,j) = (i^2)/(i+j).
0
0, 1, 76, 7032, 889920, 151876800, 33953713920, 9671337446400, 3426840152064000, 1480226878835712000, 766252171508060160000, 468506511112577236992000, 334155981137427201392640000
OFFSET
0,3
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
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, Oct 26 2004
STATUS
approved