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.

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A116897 Numbers k such that k! - k!! + 1 is prime, where k!! denotes double factorial (A006882).

Original entry on oeis.org

4, 6, 8, 14, 18, 28, 64, 324, 778, 882
Offset: 1

Views

Author

Giovanni Resta, Mar 04 2006

Keywords

Comments

Next term is greater than 3000.
Next term is greater than 15000. - Michael S. Branicky, Nov 15 2024

Examples

			6! - 6!! + 1 = 673, which is prime.

Crossrefs

Cf. A000142, A006882, A116896.

Programs

  • Mathematica
    Select[Range[900],PrimeQ[#!-#!!+1]&] (* Harvey P. Dale, Mar 27 2015 *)
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