OFFSET
1,4
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..65537
FORMULA
MAPLE
g:= proc(n) option remember; local t, x;
min(map(t -> rhs(op(t)), {msolve(x*(x+1), n)}) minus {0})
end proc:
g(1):= 1: g(2):= 1:
f:= proc(n) local d, v;
v:= g(n);
nops(select(t -> g(t) < v, numtheory:-divisors(n)))
end proc:
map(f, [$1..100]); # Robert Israel, Jun 17 2022
MATHEMATICA
s[n_] := Module[{m = 1}, While[! Divisible[m*(m + 1), n], m++]; m]; a[n_] := Module[{sn = s[n]}, DivisorSum[n, 1 &, # < n && s[#] < sn &]]; Array[a, 100] (* Amiram Eldar, Jun 17 2022 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jun 17 2022
STATUS
approved