OFFSET
1,3
COMMENTS
These are the numbers which satisfy the weak Clausen condition but not the Clausen condition.
LINKS
Ivan Neretin, Table of n, a(n) for n = 1..10000
Peter Luschny, Generalized Bernoulli numbers.
EXAMPLE
A counterexample is n = 14. 5 divides 15 but 4 does not divide 14.
MAPLE
MATHEMATICA
s[p_, n_] := Mod[n+1, p] == 0 && Mod[n, p-1] != 0; f[n_] := Select[ Select[ Range[n], PrimeQ], s[#, n] &]; A226038 = Select[ Range[0, 200], f[#] == {} &] (* Jean-François Alcover, Jul 29 2013, after Maple *)
Join[{0}, Select[Range[200], And @@ Divisible[#, FactorInteger[# + 1][[All, 1]] - 1] &]] (* Ivan Neretin, Aug 04 2016 *)
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Luschny, May 27 2013
STATUS
approved