cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A157655 Zeroless primes p such that the next prime after p can be obtained from p by adding the sum and product of the digits of p.

Original entry on oeis.org

11411, 16111, 1112113, 1151113, 14161111, 14611111, 111115141, 111253111, 115112113, 122112311, 151151111, 211711111, 1111116211, 1121123111, 1121181311, 1211215111, 1412113111, 1416131111, 2111121511, 2111215111
Offset: 1

Views

Author

Cino Hilliard, Mar 03 2009

Keywords

Comments

If we allow a zero digit in p, we generate A089824. One could conjecture that the digit 1 must always appear in the entries of this sequence. The idea for this sequence and the description was motivated by A089823.

Examples

			The digits of 11411 add up to 8. The product of the digits is 4. So 11411+8+4 = 11423, the next prime after 11411. So 11411 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    zpQ[n_]:=Module[{idn=IntegerDigits[n]},FreeQ[idn,0]&&NextPrime[n] == n+ Total[ idn]+Times@@idn]; Select[Prime[Range[11*10^7]],zpQ] (* Harvey P. Dale, Jan 14 2016 *)