A363750 Primes p such that p-1 can be written as a product of smaller numbers that are also of the form prime-1.

2, 5, 13, 17, 37, 41, 61, 73, 89, 97, 101, 109, 113, 157, 181, 193, 233, 241, 257, 277, 281, 313, 337, 349, 353, 397, 401, 409, 421, 433, 449, 457, 461, 521, 541, 577, 593, 601, 613, 617, 641, 661, 673, 701, 733, 757, 761, 769, 821, 829, 877, 881, 929, 937

Offset

1,1

Comments

Except for 2, this is a subsequence of primes of the form 4k+1 (A002144). - Davide Rotondo, Oct 07 2024

Links

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

Example

2 is a term because 2 is prime and 2-1 = 1 equals the empty product.
5 is a term because 5 is prime, 5-1 = 2*2 = (3-1)*(3-1), and 3 is prime.
3329 is a term because 3329 is prime, 3329-1 = 4*16*52 = (5-1)*(17-1)*(53-1), and 5, 17, and 53 are prime. (This is the first term that requires more than two factors.)

Crossrefs

Cf. A006093, A363636, A363638.

Cf. A002144.

Sequence in context: A124255 A293173 A079936 * A102854 A156009 A215275

Adjacent sequences: A363747 A363748 A363749 * A363751 A363752 A363753

Keyword

nonn

Author

Pontus von Brömssen, Jun 19 2023

Status

approved