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.

A108303 Numbers n such that concatenating n and the sum of the digits of n raised to their own power (A045503) produces a prime.

Original entry on oeis.org

1, 34, 41, 43, 52, 60, 67, 85, 101, 110, 113, 122, 126, 128, 146, 148, 150, 155, 168, 175, 184, 186, 191, 202, 208, 212, 234, 241, 252, 267, 287, 300, 355, 397, 404, 423, 432, 445, 469, 511, 602, 606, 620, 627, 634, 641, 656, 680, 685, 750, 762, 793, 806, 919
Offset: 1

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Author

Jason Earls, Jun 29 2005

Keywords

Comments

2^2560 produces a 782 digit prime (certified).
For purposes of this sequence, zero raised to the zero power = 1. - Harvey P. Dale, Feb 16 2020

Examples

			a(5)=52 because 5^5 + 2^2 = 3129 and 523129 is prime.
		

Crossrefs

Cf. A045503.

Programs

  • Mathematica
    cnsdQ[n_]:=Module[{idn=IntegerDigits[n]/.(0->1),c},c=Total[idn^idn];PrimeQ[n*10^IntegerLength[c]+c]]; Select[Range[1000],cnsdQ] (* Harvey P. Dale, Feb 16 2020 *)