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A342469
Positive numbers that are triangular, square or pentagonal.
0
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
1,2
PROG
(PARI) isok(m) = ispolygonal(m, 3) || ispolygonal(m, 4) || ispolygonal(m, 5);
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Marcus, Mar 13 2021
STATUS
approved