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

1,1

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.

Sequence in context: A314667 A086408 A141135 * A194395 A162502 A004766

Adjacent sequences: A363376 A363377 A363378 * A363380 A363381 A363382

Keyword

nonn,easy

Author

Neal Gersh Tolunsky, May 29 2023

Status

approved