A230808 Smallest sets of 3 consecutive odd numbers that are primes or pseudoprimes (base 2). The initial odd number is listed.

3, 641, 643, 4369, 25759, 33149, 87249, 129917, 157637, 212419, 332947, 451901, 656597, 656599, 831405, 1489665, 1608461, 2113665, 3020357, 3370637, 6212357, 6212359, 19092917, 31880577, 34487597, 38790749, 63560683, 81612105, 84028407, 86559045, 274014885

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..15437 (terms below 2^64; terms 1..5001 from Shyam Sunder Gupta)

Jan Feitsma, Tables of pseudoprimes and related data.

Example

641 is a term because {641, 643, 645} is a set of 3 consecutive odd numbers where 645 is pseudoprime to base 2 and the others are primes.

Crossrefs

Cf. A001567, A230559, A228575, A230668, A230715.

Sequence in context: A287890 A091261 A332163 * A158600 A092301 A229668

Adjacent sequences: A230805 A230806 A230807 * A230809 A230810 A230811

Keyword

nonn

Author

Shyam Sunder Gupta, Oct 30 2013

Status

approved