OFFSET
0,3
LINKS
Robert Israel, Table of n, a(n) for n = 0..10000
MAPLE
u2:= proc(n) option remember; if issqr(n) then (numtheory:-tau(n)+1)/2 else numtheory:-tau(n)/2 fi end proc:
f:= proc(n) local k; add(u2(k)*u2(n+1-k), k=1..n) end proc:
map(f, [$0..100]); # Robert Israel, Dec 05 2022
MATHEMATICA
s[n_] := s[n] = Ceiling[DivisorSigma[0, n] / 2]; a[n_] := Sum[s[k] * s[n+1-k], {k, 1, n}]; Array[a, 100, 0] (* Amiram Eldar, Apr 19 2024 *)
CROSSREFS
KEYWORD
nonn,look
AUTHOR
N. J. A. Sloane, Jan 08 2020
EXTENSIONS
Offset corrected by Robert Israel, Dec 05 2022
STATUS
approved