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

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

1,1

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".

Links

Table of n, a(n) for n=1..27.

Formula

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

Prog

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

Crossrefs

Sequence in context: A321811 A081865 A085442 * A251316 A320718 A134158

Adjacent sequences: A208546 A208547 A208548 * A208550 A208551 A208552

Keyword

nonn

Author

M. F. Hasler, Feb 28 2012

Status

approved