A373617 Positive integers that cannot be written as a sum of a practical number and a 14-gonal number.

10, 11, 14, 23, 27, 35, 39, 52, 53, 58, 76, 83, 107, 115, 125, 138, 152, 175, 178, 186, 223, 227, 262, 297, 357, 358, 373, 383, 411, 491, 502, 527, 530, 555, 788, 818, 843, 877, 915, 933, 962, 1052, 1073, 1163, 1207, 1258, 1275, 1354, 1423, 1608, 1622, 1647

Offset

1,1

Comments

Somu and Tran (2024) conjectured that there are finitely many such integers. It was also conjectured that 106878 is the largest such integer. This conjecture was checked up to 10^8.

Links

Duc Van Khanh Tran, Table of n, a(n) for n = 1..79

Sai Teja Somu and Duc Van Khanh Tran, On sums of practical numbers and polygonal numbers, Journal of Integer Sequences, 27(5), 2024.

Crossrefs

Cf. A005153, A051866.

Sequence in context: A261713 A244283 A373615 * A043583 A043773 A043779

Adjacent sequences: A373614 A373615 A373616 * A373618 A373619 A373620

Keyword

nonn,hard

Author

Duc Van Khanh Tran, Jun 11 2024

Status

approved