A342469 Positive numbers that are triangular, square or pentagonal.

1, 3, 4, 5, 6, 9, 10, 12, 15, 16, 21, 22, 25, 28, 35, 36, 45, 49, 51, 55, 64, 66, 70, 78, 81, 91, 92, 100, 105, 117, 120, 121, 136, 144, 145, 153, 169, 171, 176, 190, 196, 210, 225, 231, 247, 253, 256, 276, 287, 289, 300, 324, 325, 330, 351, 361, 376, 378, 400

Offset: 1

Author

Michel Marcus, Mar 13 2021

Keywords

• nonn

Crossrefs

Cf. A000290, A000217, A000326, A005214.

Cf. A245646, A245647, A245648.

Programs

PARI

isok(m) = ispolygonal(m,3) || ispolygonal(m,4) || ispolygonal(m,5);