A367576 Semiprimes p*q such that 2*p divides q-1.

10, 21, 26, 34, 39, 55, 57, 58, 74, 82, 93, 106, 111, 122, 129, 146, 155, 178, 183, 194, 201, 202, 203, 205, 218, 219, 226, 237, 253, 274, 291, 298, 301, 305, 309, 314, 327, 346, 355, 362, 381, 386, 394, 417, 453, 458, 466, 471, 482, 489, 497, 505, 514, 538

Offset

1,1

Comments

These terms and their squarefree proper multiples are the squarefree numbers that never appear as terms in A367566.

Links

Table of n, a(n) for n=1..54.

Example

10 is a term: 10 = 2*5, and 2*2 | 5 - 1.
33 is not a term: 33 = 3*11, but 2*3 does not divide 11 - 1.

Crossrefs

Cf. A156592, A231966, A367566.

Subsequence of A006881.

Sequence in context: A226195 A181450 A364079 * A353402 A353432 A331997

Adjacent sequences: A367573 A367574 A367575 * A367577 A367578 A367579

Keyword

nonn

Author

Jon E. Schoenfield, Nov 24 2023

Status

approved