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

11, 23, 101, 113, 131, 167, 211, 233, 311, 431, 863, 1013, 1021, 1031, 1061, 1103, 1201, 1217, 1223, 1259, 1301, 1601, 1619, 1637, 1721, 1823, 2003, 2011, 2111, 2687, 3011, 3023, 3203, 4111, 4703, 6011, 6047, 6101, 6173, 6263, 6911, 7013

Offset: 1

Author

Amarnath Murthy, Apr 04 2003

Keywords

• base
• nonn

Comments

Contains A020449 and A107612 (except 2). - Robert Israel, Nov 09 2017

Examples

			167 is a term as 168 is divisible by 1*6*7 = 42.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A020449, A081981, A081983, A081984, A081986, A081987, A107612, A101987.

Programs

Maple

filter:= proc(n)
isprime(n) and
n+1 mod convert(subs(0=NULL,convert(n,base,10)),`*`) = 0
end proc:
select(filter, [seq(i,i=3..10000,2)]); # Robert Israel, Nov 09 2017

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

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 06 2003