OFFSET
0,3
COMMENTS
The next 1 after a(1), a(3) and a(15) occurs at n=224, as A000217(224) = 25200 = 5 * 7!.
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..10000
FORMULA
MATHEMATICA
a[n_] := Module[{k = n*(n+1)/2, m = 2, r, s = {}}, While[{k, r} = QuotientRemainder[k, m]; k != 0|| r != 0, AppendTo[s, r]; m++]; Count[s, _?(# > 0 &)]]; Array[a, 100, 0] (* Amiram Eldar, Feb 07 2024 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, Nov 18 2013
STATUS
approved