A348471 One half of the even numbers without middle divisors.

5, 7, 11, 13, 17, 19, 22, 23, 26, 29, 31, 34, 37, 38, 39, 41, 43, 46, 47, 51, 53, 57, 58, 59, 61, 62, 67, 68, 69, 71, 73, 74, 76, 79, 82, 83, 86, 87, 89, 92, 93, 94, 97, 101, 103, 106, 107, 109, 111, 113, 115, 116, 118, 122, 123, 124, 125, 127, 129, 131, 134, 137, 139, 141

Offset: 1

Author

Omar E. Pol, Oct 19 2021

Keywords

• nonn

Comments

One half of the even numbers k such that the symmetric representation of sigma(k) has an even number of parts.

Crossrefs

First differs from A101550 at a(57).

A subsequence is A320048 from which first differs at a(51).

Cf. A071561, A237270, A237271, A237593, A244894, A319802.

Formula

a(n) = A319802(n)/2.