cp's OEIS Frontend

A081982 Primes p such that p+1 is divisible by the digital product (of nonzero digits) of p.

%I A081982 #14 Nov 10 2017 21:14:28
%S A081982 11,23,101,113,131,167,211,233,311,431,863,1013,1021,1031,1061,1103,
%T A081982 1201,1217,1223,1259,1301,1601,1619,1637,1721,1823,2003,2011,2111,
%U A081982 2687,3011,3023,3203,4111,4703,6011,6047,6101,6173,6263,6911,7013
%N A081982 Primes p such that p+1 is divisible by the digital product (of nonzero digits) of p.
%C A081982 Contains A020449 and A107612 (except 2). - _Robert Israel_, Nov 09 2017
%H A081982 Robert Israel, <a href="/A081982/b081982.txt">Table of n, a(n) for n = 1..10000</a>
%e A081982 167 is a term as 168 is divisible by 1*6*7 = 42.
%p A081982 filter:= proc(n)
%p A081982 isprime(n) and
%p A081982 n+1 mod convert(subs(0=NULL,convert(n,base,10)),`*`) = 0
%p A081982 end proc:
%p A081982 select(filter, [seq(i,i=3..10000,2)]); # _Robert Israel_, Nov 09 2017
%o A081982 (PARI) isok(p) = isprime(p) && (d=digits(p)) && !((p+1) % prod(k=1, #d, if (d[k], d[k], 1))); \\ _Michel Marcus_, Nov 09 2017
%Y A081982 Cf. A020449, A081981, A081983, A081984, A081986, A081987, A107612, A101987.
%K A081982 base,nonn
%O A081982 1,1
%A A081982 _Amarnath Murthy_, Apr 04 2003
%E A081982 More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 06 2003