A342738 Primes p such that A001414(p+1) = A001414(p-1) + 1.

5, 7, 19, 41, 197, 2549, 4159, 8467, 9433, 26701, 27551, 46817, 57037, 91097, 130859, 153281, 157049, 197683, 351727, 423103, 466181, 517991, 526291, 567181, 575231, 652903, 663167, 772339, 1055231, 1062013, 1088239, 1171199, 1232461, 1551871, 1603297, 1662833, 2782469, 2920531, 2957917, 3226159

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..1000

Example

a(3) = 19 is a term because it is prime and A001414(20) = 9 = 1 + A001414(18).

Maple

spf:= proc(n) local t; add(t[1]*t[2], t=ifactors(n)[2]) end proc:
select(p -> spf(p+1)=spf(p-1)+1, [seq(ithprime(i), i=1..10^5)]);

Crossrefs

Cf. A001414, A086711, A342823.

Sequence in context: A146470 A296935 A106987 * A321510 A084198 A036061

Adjacent sequences: A342735 A342736 A342737 * A342739 A342740 A342741

Keyword

nonn

Author

J. M. Bergot and Robert Israel, Mar 22 2021

Status

approved