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.

A057447 a(n+1) = next prime such that a(n+1)-1 | (a(1)...a(n))^3.

Original entry on oeis.org

2, 3, 5, 7, 11, 13, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 101, 107, 109, 127, 131, 139, 149, 151, 157, 167, 173, 179, 181, 191, 197, 199, 211, 223, 229, 233, 251, 263, 269, 271, 277, 281, 283, 293, 311, 313, 317, 331, 347, 349, 359
Offset: 1

Views

Author

Robert G. Wilson v, Sep 25 2000

Keywords

Comments

No prime of the form a*b^k + 1, with a > 0, b > 1 and k > 3 (including those in A037896) belongs to the sequence. - Mauro Fiorentini, Aug 09 2023

Crossrefs

Programs

  • Mathematica
    NextPrime[ n_Integer ] := Module[ {k = n + 1}, While[ ! PrimeQ[ k ], k++ ]; Return[ k ] ]; f[ n_List ] := (a = n; b = Apply[ Times, a^3 ]; d = NextPrime[ a[[ -1 ]] ]; While[ ! IntegerQ[ b/(d - 1) ] && d < b+2, d = NextPrime[ d ] ]; AppendTo[ a, d ]; Return[ a ]); Nest[ f, {2}, 75 ]