A230808 Smallest sets of 3 consecutive odd numbers that are primes or pseudoprime (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

Author

Shyam Sunder Gupta, Oct 30 2013

Keywords

• nonn

Examples

			641 is in sequence because 641, 643, 645 is a set of 3 consecutive odd number where 645 is pseudoprime base 2 and others are prime.
		

Links

• Shyam Sunder Gupta, Table of n, a(n) for n = 1..5001
• Jan Feitsma, Tables of pseudoprimes and related data

Crossrefs

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