Heptagonal numbers are figurate numbers based on a 7-sided polygon, given by \(\text{Hep}_k = k(5k-3)/2\) for \(k \geq 1\). First terms: 1, 7, 18, 34, 55, 81, 112, 148, 189, 235.
Term
Heptagonal
Figurate numbers k(5k−3)/2 (1, 7, 18, 34, 55, 81, 112, 148, …).
30 numbers tagged.