A363379 Numbers k such that the sum of the first k terms of A180405 is composite.

5, 9, 13, 17, 21, 25, 27, 33, 41, 47, 55, 61, 65, 69, 75, 83, 89, 95, 105, 107, 113, 119, 125, 128, 133, 139, 145, 155, 161, 165, 171, 179, 183, 189, 197, 201, 207, 211, 217, 225, 231, 237, 241, 247, 255, 261, 267, 271, 279, 285, 289, 297, 303, 307, 313, 319, 327, 333, 339, 343, 351

Offset: 1

Author

Neal Gersh Tolunsky, May 29 2023

Keywords

• nonn
• easy

Comments

The construction in A180405 means terms here cannot be terms there, but do any other numbers never occur there?

Indices of composite terms in A363450 (partial sums of A180405).

a(24)=128 is possibly the only even term in the sequence (checked for 6000 terms).

Links

• Neal Gersh Tolunsky, Table of n, a(n) for n = 1..6098

Crossrefs

Cf. A180405, A363450.