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

1,1

Comments

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

Links

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

Formula

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

Example

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

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]));

Crossrefs

Cf. A340736, A340740, A340741.

Sequence in context: A053789 A115596 A202033 * A029610 A279967 A094246

Adjacent sequences: A340739 A340740 A340741 * A340743 A340744 A340745

Keyword

nonn

Author

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

Status

approved