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A279917
a(n) = Sum_{k=1..n-1} sigma_5(k)*sigma_7(n-k).
3
0, 1, 162, 6689, 121250, 1296406, 9613604, 54550049, 252178758, 992204376, 3424910566, 10615778966, 30047257318, 78751366604, 193075366412, 446840757793, 982597838280, 2066025009763, 4171924730922, 8127978871064, 15324653827568, 28059983210370
OFFSET
1,3
LINKS
FORMULA
a(n) = (sigma_13(n)+20*sigma_7(n)-21*sigma_5(n))/10080.
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Dec 23 2016
STATUS
approved