A373615 Positive integers that cannot be written as a sum of a practical number and an 11-gonal number.

10, 11, 14, 22, 26, 44, 45, 52, 63, 68, 69, 87, 92, 93, 116, 117, 152, 164, 172, 182, 188, 194, 233, 242, 243, 247, 248, 259, 279, 327, 374, 377, 402, 434, 482, 517, 579, 629, 712, 752, 759, 777, 824, 852, 934, 997, 1209, 1238, 1287, 1314, 1454, 1602, 1804

Offset

1,1

Comments

Somu and Tran (2024) conjectured that there are finitely many such integers. It was also conjectured that 105712 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..68

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, A051682.

Sequence in context: A144980 A261713 A244283 * A373617 A043583 A043773

Adjacent sequences: A373612 A373613 A373614 * A373616 A373617 A373618

Keyword

nonn,hard

Author

Duc Van Khanh Tran, Jun 11 2024

Status

approved