OFFSET
2,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 2..10000
FORMULA
a(n) ~ A026011(n). - Vaclav Kotesovec, Feb 20 2021
MAPLE
g:= proc(n) option remember; `if`(n=0, 1, add(g(n-j)*add(d^2/
`if`(d::odd, 1, 2), d=numtheory[divisors](j)), j=1..n)/n)
end:
b:= proc(n, k) option remember; `if`(k=0, 1, `if`(k=1, `if`(n=0, 0,
g(n)), (q-> add(b(j, q)*b(n-j, k-q), j=0..n))(iquo(k, 2))))
end:
a:= n-> b(n, 2):
seq(a(n), n=2..34); # Alois P. Heinz, Feb 10 2021
MATHEMATICA
nmax = 34; CoefficientList[Series[(-1 + Product[(1 + x^k)^k, {k, 1, nmax}])^2, {x, 0, nmax}], x] // Drop[#, 2] &
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Feb 10 2021
STATUS
approved