A379804 By definition, |A379803(k)| is twice a perfect square, say 2*b(k)^2. The values of b(k) appear to be the consecutive natural numbers 1, 2, 3, ... except that the numbers in the present sequence are omitted.

14, 15, 18, 45, 51, 52, 54, 58, 59, 60, 61, 62, 65, 71, 101, 102, 104, 106, 111, 114, 117, 120, 121, 122, 123, 124, 125, 126, 128, 130, 141, 161, 164, 176, 189, 203, 204, 213, 215, 229, 241, 256, 261, 262, 281, 284, 301, 306, 307, 310, 311, 312, 314, 315, 316

Offset

1,1

Comments

The sequence {b(k): k >= 1} begins 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 16, 17, 19, 20, ..., and as can be seen, 14, 15, and 18 are missing.

The values of b(k) are distinct.

Links

Rémy Sigrist, Table of n, a(n) for n = 1..5000

Rémy Sigrist, C++ program

Prog

(C++) // See Links section.

Crossrefs

Cf. A377091, A379066, A379788-A379794, A379802, A379803.

Sequence in context: A173687 A114962 A278979 * A220671 A136012 A038456

Adjacent sequences: A379801 A379802 A379803 * A379805 A379806 A379807

Keyword

nonn

Author

N. J. A. Sloane, Jan 19 2025

Extensions

More terms from Rémy Sigrist, Feb 09 2025

Status

approved