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

1,1

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

Links

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

Example

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

Mathematica

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

Crossrefs

Cf. A000040, A028834, A028842.

Sequence in context: A062713 A334630 A086108 * A344454 A235153 A177968

Adjacent sequences: A052427 A052428 A052429 * A052431 A052432 A052433

Keyword

base,nonn

Author

Henry Bottomley, Mar 14 2000

Status

approved