A326655 Numbers k such that 3*4^k+1 is prime.

1, 3, 4, 6, 9, 15, 18, 33, 138, 204, 219, 267, 1104, 1408, 1584, 1956, 17175, 21147, 24075, 27396, 27591, 40095, 354984, 400989, 916248, 1145805, 2541153, 5414673

Offset

1,2

Comments

One half of the even terms in A002253.

Links

Table of n, a(n) for n=1..28.

Crossrefs

Numbers k such that r*(r+1)^k+1 is prime: A003306 (r=2), this sequence (r=3), A204322 (r=4), A247260 (r=5), A245241 (r=6), A269544 (r=7), A056799 (r=8), A056797 (r=9), A057462 (r=10), A251259 (r=11).

Sequence in context: A147790 A048577 A107340 * A291866 A394699 A332829

Adjacent sequences: A326652 A326653 A326654 * A326656 A326657 A326658

Keyword

nonn,more

Author

Eric Chen, Jul 16 2019

Status

approved