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.

Showing 1-3 of 3 results.

A221699 Numbers with property that each sum any pair of digits is prime.

Original entry on oeis.org

11, 12, 14, 16, 20, 21, 23, 25, 29, 30, 32, 34, 38, 41, 43, 47, 49, 50, 52, 56, 58, 61, 65, 67, 70, 74, 76, 83, 85, 89, 92, 94, 98, 111, 112, 114, 116, 121, 141, 161, 203, 205, 211, 230, 250, 302, 320, 411, 502, 520, 611, 1111, 1112, 1114, 1116, 1121, 1141, 1161
Offset: 1

Views

Author

Jaroslav Krizek, Jan 22 2013

Keywords

Comments

Supersequence of A091939. Subsequence of A182175.

Examples

			Number 203 is a term because 2+3=5, 2+0=2, 3+0=3 (primes).

Links

Crossrefs

Cf. A172508, A091939, A182175.

Programs

  • Mathematica
    fQ[n_] := Module[{d = IntegerDigits[n]}, Union[PrimeQ[Plus @@@ Union[Subsets[d, {2}]]]] == {True}]; Select[Range[6000], fQ] (* T. D. Noe, Jan 24 2013 *)
Select[Range[10,1200],AllTrue[Total/@Subsets[IntegerDigits[#],{2}],PrimeQ]&] (* Harvey P. Dale, Jan 31 2024 *)

A181525 Prime numbers such that the difference between any pair of digits is 0, 2, 3, 5 or 7.

Original entry on oeis.org

2, 3, 5, 7, 11, 13, 29, 31, 41, 47, 53, 61, 79, 83, 97, 113, 131, 163, 181, 227, 229, 257, 277, 311, 313, 331, 353, 383, 449, 461, 479, 499, 503, 557, 577, 613, 631, 641, 661, 683, 727, 757, 797, 811, 853, 863, 881, 883, 929, 947, 977, 997, 1163, 1181, 1361
Offset: 1

Views

Author

Robert G. Wilson v, Oct 26 2010

Keywords

Crossrefs

Cf. A172508, A181526.

Programs

  • Mathematica
    fQ[n_] := Union[ MemberQ[ {0, 2, 3, 5, 7}, # ] & /@ (Subtract @@ Sort[ #, Greater] & /@ Subsets[ IntegerDigits@ n, {2}])] == {True} && PrimeQ@ n; Select[ Range@ 1380, fQ]

A181526 Prime numbers such that the difference between any pair of digits is 1, 2, 3, 5 or 7.

Original entry on oeis.org

2, 3, 5, 7, 13, 23, 29, 31, 41, 43, 47, 53, 61, 67, 79, 83, 89, 97, 103, 163, 241, 257, 421, 431, 457, 461, 463, 467, 479, 503, 523, 547, 563, 587, 613, 631, 641, 643, 647, 653, 683, 769, 853, 857, 863, 947, 967, 1423, 2053, 2143, 2341, 2503, 2543, 2749, 3461
Offset: 1

Views

Author

Robert G. Wilson v, Oct 26 2010

Keywords

Crossrefs

Cf. A172508, A181525.

Programs

  • Mathematica
    fQ[n_] := Union[ MemberQ[ {1, 2, 3, 5, 7}, # ] & /@ (Subtract @@ Sort[ #, Greater] & /@ Subsets[ IntegerDigits@ n, {2}])] == {True} && PrimeQ@ n; Select[ Range@ 4230, fQ]
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement.