A348244 Indices of 1's in A307720.

1, 2, 4, 6, 48, 50, 52, 54, 56, 58, 1375, 1377, 1379, 1381, 1383, 1385, 1387, 1389, 1391, 1393, 1395, 1397, 3739, 3741, 3743, 3745, 3747, 3749, 3751, 3753, 3755, 3757, 3759, 3761, 3763, 3765, 3767, 3769, 3771, 3773, 6681, 6683, 6685, 6687, 6689, 6691, 6693, 6695, 6697, 6699, 6701, 6703, 6705

Offset

1,2

Comments

Theorem: This sequence is infinite. Proof: Every prime in A307720 is immediately preceded or followed by a 1. - N. J. A. Sloane, Oct 30 2021

The start of this sequence consists of arithmetic progressions of constant difference 2 and lengths 1, 3, 6, 12, 18, 26, 76, ... that start with 1, 2, 48, 1375, 3739, 6681, 84627, 91833, ... It would be nice to have an alternative way to explain these numbers.

Links

N. J. A. Sloane, Table of n, a(n) for n = 1..927

Crossrefs

Cf. A307720.

Sequence in context: A329529 A333456 A377700 * A381085 A066220 A348152

Adjacent sequences: A348241 A348242 A348243 * A348245 A348246 A348247

Keyword

nonn

Author

N. J. A. Sloane, Oct 16 2021

Status

approved