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 A177890 15-gonal (or pentadecagonal) pyramidal numbers:  a(n) = n*(n+1)*(13*n-10)/6. 2
 0, 1, 16, 58, 140, 275, 476, 756, 1128, 1605, 2200, 2926, 3796, 4823, 6020, 7400, 8976, 10761, 12768, 15010, 17500, 20251, 23276, 26588, 30200, 34125, 38376, 42966, 47908, 53215, 58900, 64976, 71456, 78353, 85680, 93450, 101676, 110371, 119548, 129220 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Also a(n) = (15-m)*A000292(n-1)+n*(n+1)*((m-2)*n-(m-5))/6 being n*(n+1)*((m-2)*n-(m-5))/6 a m-gonal pyramidal number (1

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