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.

A208549 Numbers m such that 2520*m/k + 1 is a prime for k = 1,...,7.

Original entry on oeis.org

2189, 7208, 20538, 69632, 127790, 265375, 341267, 461849, 621457, 1453179, 1700469, 1828994, 1837608, 2114852, 2222674, 2354838, 2826692, 2905552, 2933084, 3162302, 3466663, 3972552, 3996543, 4535984, 5382039, 6192528, 6392223
Offset: 1

Views

Author

M. F. Hasler, Feb 28 2012

Keywords

Comments

Equivalently, 7!*m/2+k equals k times a prime, for k=1,...,7. The primes 2520m+1 are listed in A207825, and are also the terms of the sequence A071369 which end in the digit "1".

Programs

  • PARI
    {my(p=1); until(, isprime(p+=2520) || next; for(j=2,7, isprime(p\j+1)||next(2)); print1(p\2520", "))}

Formula

A208549(n) = (A207825(n)-1)/2520.