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.

A331346 Primes using all the square digits {0, 1, 4, 9} and no others.

Original entry on oeis.org

1049, 1409, 4019, 4091, 9041, 10499, 10949, 14009, 49019, 49109, 90149, 90401, 94109, 99041, 99401, 100049, 101149, 101419, 101449, 104009, 104119, 104149, 104491, 104911, 104999, 109049, 109141, 109441, 110419, 110491, 111049, 111409, 114901, 140009, 140191, 140419
Offset: 1

Views

Author

K. D. Bajpai, Jan 14 2020

Keywords

Comments

Subsequence of A061246.

Examples

			a(1) = 1049 is prime containing all the square digits (0, 1, 4, 9) and no others.
a(2) = 1409 is prime containing all the square digits (0, 1, 4, 9) and no others.
		

Crossrefs

Programs

  • Magma
    [p:p in PrimesUpTo(150000)|Set(Intseq(p)) eq {0,1,4,9}]; // Marius A. Burtea, Jan 14 2020
  • Maple
    f:= proc(n) local L,x;
      L:= convert(n,base,4);
      if convert(L,set) <> {0,1,2,3} then return NULL fi;
      L:= subs(2=4,3=9,L);
      x:= add(L[i]*10^(i-1),i=1..nops(L));
      if isprime(x) then x else NULL fi
    end proc:
    map(f, [$4^3..4^6]); # Robert Israel, Jan 16 2020
  • Mathematica
    Select[FromDigits /@ Tuples[{0, 1, 4, 9}, 6], PrimeQ[#] && Union[IntegerDigits[#]] == {0, 1, 4, 9} &]