A342823 Primes p such that A001414(p+1) = A001414(p-1) - 1.

29, 127, 449, 571, 727, 1721, 4027, 11969, 16987, 18913, 26449, 37139, 43609, 48871, 48953, 63799, 64781, 114479, 180847, 220021, 400031, 400597, 476911, 607549, 679969, 705883, 706841, 770059, 776449, 807539, 912367, 932177, 964793, 1007959, 1052237, 1095851, 1356227, 1444567, 1573339, 1664633

Offset: 1

Author

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

Keywords

• nonn

Examples

			a(3) = 449 is a term because it is prime and A001414(450) = 18 = A001414(448) - 1.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..1100

Crossrefs

Cf. A001414, A086711, A342738.

Programs

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)]);