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.

A179911 Primes with three embedded primes.

Original entry on oeis.org

113, 131, 179, 197, 223, 233, 239, 257, 271, 283, 293, 311, 313, 337, 347, 353, 359, 367, 397, 431, 479, 547, 571, 593, 613, 617, 653, 719, 733, 739, 743, 773, 797, 823, 853, 937, 953, 971, 1013, 1031, 1097, 1103, 1117, 1129, 1151, 1163, 1213, 1217, 1229
Offset: 1

Views

Author

Robert G. Wilson v, Aug 01 2010

Keywords

Comments

A079066(a(n)) = 3.

Crossrefs

Programs

  • Haskell
    import Data.List (elemIndices)
    a179911 n = a179911_list !! (n-1)
    a179911_list = map (a000040 . (+ 1)) $ elemIndices 3 a079066_list
    -- Reinhard Zumkeller, Jul 19 2011
  • Mathematica
    f[n_] := Block[ {id = IntegerDigits@n}, len = Length@ id - 1; Count[ PrimeQ@ Union[ FromDigits@# & /@ Flatten[ Table[ Partition[ id, k, 1], {k, len}], 1]], True] + 1]; Select[ Prime@ Range@ 210, f@# == 4 &]