A363638 Primes p such that p+1 can be written as a product of smaller numbers that are also of the form prime+1.

11, 17, 23, 31, 41, 47, 53, 59, 71, 79, 83, 89, 107, 113, 127, 131, 151, 167, 179, 191, 223, 227, 239, 251, 263, 269, 271, 293, 311, 359, 383, 419, 431, 439, 443, 449, 479, 491, 503, 521, 557, 587, 593, 599, 607, 631, 647, 659, 683, 701, 719, 727, 743, 773

Offset

1,1

Links

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

Example

11 is a term because 11 is prime, 11+1 = 3*4 = (2+1)*(3+1), and 2 and 3 are prime.
223 is a term because 223 is prime, 223+1 = 4*4*14 = (3+1)^2*(13+1), and 3 and 13 are prime. (This is the first term that requires more than two factors, i.e., it is not a term of A066938.)

Crossrefs

Cf. A008864, A066938 (subsequence), A363636, A363750.

Sequence in context: A337359 A275596 A158913 * A066938 A219602 A242260

Adjacent sequences: A363635 A363636 A363637 * A363639 A363640 A363641

Keyword

nonn

Author

Pontus von Brömssen, Jun 19 2023

Status

approved