login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A345932
a(n) = A002034(n) / gcd(n, A002034(n)), where A002034(n) gives the smallest positive integer k such that n divides k!.
3
1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 3
OFFSET
1,9
FORMULA
a(n) = A002034(n) / A345931(n) = A002034(n) / gcd(n, A002034(n))
MATHEMATICA
Table[s=(m=1; While[Mod[m!, n]!=0, m++]; m); s/GCD[n, s], {n, 100}] (* Giorgos Kalogeropoulos, Jul 02 2021 *)
PROG
(PARI)
A002034(n) = if(1==n, n, my(s=factor(n)[, 1], k=s[#s], f=Mod(k!, n)); while(f, f*=k++); (k)); \\ After code in A002034.
A345932(n) = { my(u=A002034(n)); (u/gcd(n, u)); };
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jul 01 2021
STATUS
approved