OFFSET
1,3
FORMULA
a(p) = p - 1 for p prime. - Petros Hadjicostas, May 11 2020
EXAMPLE
2 is the smallest prime dividing 12. Among the first 11 terms of the sequence there are 4 terms (1, 1, 7, 3) that are not divisible by 2. So a(12) = 4.
MATHEMATICA
f[s_] := Append[s, Length@ Select[s, Mod[ #, FactorInteger[1 + Length@s][[1, 1]]] != 0 &]]; Nest[f, {1}, 76] (* Robert G. Wilson v *)
PROG
(PARI) {m=78; print1(a=1, ", "); v=[a]; for(n=2, m, p=factor(n)[1, 1]; a=0; for(j=1, n-1, if(v[j]%p>0, a++)); print1(a, ", "); v=concat(v, a))} \\ Klaus Brockhaus, Aug 15 2006
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Aug 09 2006
EXTENSIONS
More terms from Klaus Brockhaus and Robert G. Wilson v, Aug 15 2006
STATUS
approved