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.

A290045 Primes in A290044.

Original entry on oeis.org

7, 41, 176075177, 49127973630377
Offset: 1

Views

Author

XU Pingya, Jul 19 2017

Keywords

Comments

For n < 20, A290044(n) are prime when n = {2, 3, 9, 13}.
For n >= 20, 19|A290044(n). Therefore there are only 4 terms in this sequence.

Examples

			41 = |0!! - 2!! + 4!! - 6!!| is prime.
		

Crossrefs

Programs

  • Mathematica
    Select[Table[Abs@ Sum[(-1)^k*(2 k)!!, {k, 0, n}], {n, 0, 60}], PrimeQ] (* Michael De Vlieger, Jul 19 2017 *)