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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A073827 Numbers n such that 1 + 0!*1!*2!*...*n! is prime.

Original entry on oeis.org

0, 1, 2, 3, 7, 14
Offset: 1

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Author

Rick L. Shepherd, Aug 16 2002

Keywords

Comments

Any additional terms are greater than 115 with the next prime having 9744 or more digits.

Crossrefs

Cf. A073828 (corresponding primes), A000178 (superfactorials), A019515.

Programs

  • PARI
    pr=1; for(n=0,115, pr=pr*n!; if(isprime(pr+1), print1(n,",")))

A110094 Startorial primes.

Original entry on oeis.org

2, 3, 5, 7, 23, 719, 5039, 1451521, 2903041, 5806081, 46448639, 92897281, 371589121, 10032906239, 30098718719, 270888468479, 812665405439, 7313988648961, 21941965946881, 89874292518420479
Offset: 1

Views

Author

Jonathan Vos Post, Sep 04 2005

Keywords

Comments

These are primes of the form A109834 startorials (base 10) +1 or -1. This is by analogy to factorial primes (A002981), superfactorial primes (A073828), hyperfactorial primes, ultrafactorial primes (comment in A046882), subfactorial primes (A100015), double factorial primes (A080778), multifactorial primes (A037083).

Crossrefs

Cf. A000040, A002981, A073828, A080778, A037083, A100015, A103317, A046882, A109834.

Formula

{a(n)} = {A109834(k)+1 an element of A000040, or A109834(k)-1 an element of A000040, for some k}.
Showing 1-2 of 2 results.

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