A229966 Numbers n such that A229964(n) = 3.

12, 14, 22, 27, 33, 57, 85, 161, 203, 533, 689, 901, 1121, 1633, 2581, 4181, 5513, 5633, 7439, 10561, 18023, 18881, 20833, 21389, 23941, 25043, 28421, 32033, 37733, 48641, 58241, 64643, 66901, 77423, 80033, 84001, 90133, 106439, 116821, 119201, 149189, 155041

Offset

1,1

Comments

Equals {12, 14, 22, 27, 57} UNION {pq | p, q prime, q = 3p+2 or (p >= 5 and q = 4p+1)}.

Links

Eric M. Schmidt, Table of n, a(n) for n = 1..1000

Rosemary Sullivan and Neil Watling, Independent Divisibility Pairs on the Set of Integers from 1 to N, INTEGERS, Electronic J. of Combinatorial Number Theory, Vol. 13, Paper A65, 2013.

Prog

(Sage) [p * (3*p+2) for p in prime_range(10000) if (3*p+2).is_prime()] + [p * (4*p+1) for p in prime_range(5, 10000) if (4*p+1).is_prime()] + [12, 14, 22, 27, 57]

Crossrefs

Cf. A166684, A082663, A229965, A229967, A023208, A023212.

Sequence in context: A257966 A342814 A255842 * A342491 A101557 A019292

Adjacent sequences: A229963 A229964 A229965 * A229967 A229968 A229969

Keyword

nonn

Author

Eric M. Schmidt, Oct 04 2013

Status

approved