A356260 Lower twin primes p such that (p^2 + (p+2)^2)/10 is prime.

11, 41, 101, 107, 197, 311, 461, 521, 827, 1061, 1277, 1451, 1487, 1871, 2027, 2141, 2801, 3251, 3671, 4091, 4547, 5651, 5657, 6197, 6791, 6827, 7307, 7457, 8837, 9011, 9041, 9437, 9857, 10007, 10301, 10457, 11777, 12041, 12251, 12611, 13691, 13721, 13997, 14321, 14387, 15287, 15641, 17027, 17747

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

a(3) = 101 is a term because 101 and 103 are primes and (101^2 + 103^2)/10 = 2081 is prime.

Maple

P:= select(isprime, {seq(i, i=3..10^5, 2)}):
T:=P intersect map(`-`, P, 2):
filter:= proc(t) local s; s:= (t^2 + (t+2)^2)/10; s::integer and isprime(s) end proc:
sort(convert(select(filter, T), list));

Mathematica

Select[Prime[Range[2000]], And @@ PrimeQ[{# + 2, (#^2 + (# + 2)^2)/10}] &] (* Amiram Eldar, Aug 01 2022 *)

Crossrefs

Cf. A001359.

Sequence in context: A239462 A065145 A030685 * A132208 A233434 A261538

Adjacent sequences: A356257 A356258 A356259 * A356261 A356262 A356263

Keyword

nonn

Author

J. M. Bergot and Robert Israel, Jul 31 2022

Status

approved