A052430 Numbers n such that sum of digits and product of digits are both prime.

2, 3, 5, 7, 12, 21, 113, 115, 131, 151, 311, 511, 1112, 1121, 1211, 2111, 11113, 11117, 11131, 11171, 11311, 11711, 13111, 17111, 31111, 71111, 111112, 111121, 111211, 112111, 121111, 211111, 1111115, 1111117, 1111151, 1111171, 1111511, 1111711

Offset: 1

Author

Henry Bottomley, Mar 14 2000

Keywords

• base
• nonn

Comments

One digit must be 2, 3, 5, or 7 and every other digit must be 1. If k is in the sequence, then so is every permutation of the digits of k. - Sean A. Irvine, Nov 08 2021

Examples

			a(7)=115 because 1+1+5=7 which is prime and 1*1*5=5 which is prime
		

Links

• Sean A. Irvine, Table of n, a(n) for n = 1..994

Crossrefs

Cf. A000040, A028834, A028842.

Programs

Mathematica

okQ[n_]:=Module[{idn=IntegerDigits[n]},PrimeQ[Total[idn]]&&PrimeQ[Times@@idn]]
Select[Range[1500000],okQ] (* Harvey P. Dale, Dec 15 2010 *)