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A098612
Sum of all matrix elements M(i,j) = (i^2)/(i+j) multiplied by (2*n)!/n!.
0
0, 1, 38, 1172, 37080, 1265640, 47157936, 1918916160, 84991075200, 4079108462400, 211158556963200, 11737075895677440, 697609321424870400, 44168292113326617600, 2968571902157455104000, 211131415096140736512000
OFFSET
0,3
FORMULA
a(n) = (2*n)!/n!*Sum[Sum[(i^2)/(i+j), {i, 1, n}], {j, 1, n}]
MATHEMATICA
Table[(2*n)!/n!*Sum[Sum[(i^2)/(i+j), {i, 1, n}], {j, 1, n}], {n, 0, 15}]
CROSSREFS
Sequence in context: A285236 A208949 A255496 * A268739 A239043 A137030
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, Oct 26 2004
STATUS
approved