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.

A278699 Primes p such that every suffix of the base-4 representation of p is a prime.

Original entry on oeis.org

2, 3, 7, 11, 19, 23, 43, 59, 67, 71, 83, 107, 131, 139, 151, 199, 211, 251, 263, 467, 523, 571, 619, 643, 787, 811, 827, 839, 907, 919, 967, 1019, 1031, 1091, 1163, 1223, 1667, 1811, 1931, 2131, 2179, 2311, 2887, 3067, 3079, 3083, 3203, 3271, 3323, 3539, 3643, 3691, 3911, 4091, 4099, 4139
Offset: 1

Views

Author

Randy L. Ekl, Nov 26 2016

Keywords

Comments

All numbers in the sequence are of the form 4n+3, except the number 2.

Examples

			23 is in the sequence, since 23 is prime, and the suffixes of 23 (113 base 4), 13 base 4 (7 base 10) and 3, are all prime.
		

Programs

  • Mathematica
    With[{b = 4}, Select[Prime@ Range[10^3], Function[k, Times @@ Boole@ Map[PrimeQ@ FromDigits[Take[k, -#], b] &, Range[Length@ k - 1]] == 1]@ IntegerDigits[#, b] &]] (* Michael De Vlieger, Dec 01 2016 *)