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A098607
Sum of all matrix elements M(i,j) = (i*j)/(i+j) multiplied by (2*n)!/n!.
0
0, 1, 34, 988, 30120, 1002360, 36667344, 1471350720, 64457424000, 3066397905600, 157584858076800, 8706059034140160, 514786845983155200, 32448410132597222400, 2172454153870807296000, 153986353780968511488000
OFFSET
0,3
FORMULA
a(n) = (2*n)!/n!*Sum[Sum[(i*j)/(i+j), {i, 1, n}], {j, 1, n}]
MATHEMATICA
Table[(2*n)!/n!*Sum[Sum[(i*j)/(i+j), {i, 1, n}], {j, 1, n}], {n, 0, 15}]
CROSSREFS
Sequence in context: A212787 A020535 A134500 * A075292 A297456 A328350
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, Oct 26 2004
STATUS
approved