A340742 Primes in A340740, in the order in which they occur.

2, 2, 2, 7, 2, 7, 5, 7, 19, 13, 47, 31, 31, 17, 53, 41, 127, 79, 61, 113, 103, 229, 149, 73, 257, 383, 173, 613, 263, 293, 439, 541, 787, 883, 1039, 647, 643, 1129, 1151, 1181, 769, 1153, 1303, 1559, 2153, 2221, 2393, 3881, 1427, 1429, 4211, 3691, 1291, 3919, 1549, 2371, 4691, 4909, 2251, 2713, 2143, 4957, 3863, 4073, 4337

Offset: 1

Author

J. M. Bergot and Robert Israel, Jan 18 2021

Keywords

• nonn

Comments

Terms occurring more than once include 2, 7, 31, and 4073. Are there any others?

Examples

			a(3) = A340740(9) = 2.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A340736, A340740, A340741.

Programs

Maple

f:= proc(n) local k;
  add(`if`(igcd(k, n)=1, n mod k, 0), k=1..floor(n/2))
end proc:
select(isprime, map(f, [$1..1000]));

Formula

a(n) = A340740(A340741(n)).