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.

A129250 Primes of Erdős-Selfridge class 16-.

Original entry on oeis.org

22111003847, 25782283783, 34824831403, 42970472971, 44905511759, 45490491349, 52486961911, 54560052479, 55437374381, 65803884467, 66333011539
Offset: 1

Views

Author

M. F. Hasler, Apr 21 2007

Keywords

Comments

Knowledge of a(k), k=1..9 allows us to establish A056637(17) = 1 + 2*a(9) = 110874748763.

Crossrefs

Programs

  • PARI
    nextclass( a, s=-1, p, n=[] )={ if( !p, p=nextprime(a[ #a]+1)); print("Computing all primes of next class up to ",2*p-s ); for( i=1,#a, for( k=1,p/a[i], if( is/*pseudo*/prime(2*k*a[i]-s), n=concat(n,2*k*a[i]-s); ) ) ); vecsort(n) }; A129250=nextclass(A129249)

Formula

{ a(n) } = { p=1+2*k*A129249(n); n=1,2,3..., k=1,2,3... such that p is prime and k has no factor of class > 15- }.