A342772 Row sums of triangle A177028.

3, 4, 5, 9, 7, 8, 13, 13, 11, 17, 13, 14, 24, 20, 17, 25, 19, 20, 32, 27, 23, 33, 29, 26, 37, 37, 29, 41, 31, 32, 45, 41, 40, 56, 37, 38, 53, 48, 41, 57, 43, 44, 70, 55, 47, 65, 53, 50, 74, 62, 53, 73, 65, 56, 77, 69, 59, 81, 61, 62, 85, 80, 73, 98, 67, 68, 93, 88, 71, 97

Offset: 3

Author

Michel Marcus, Mar 21 2021

Keywords

• nonn

Examples

			6 is a triangular and hexagonal number, so a(6) = 3 + 6 = 9.
		

Links

• Michel Marcus, Table of n, a(n) for n = 3..10000

Crossrefs

Cf. A090466, A090467, A177028.

Programs

PARI

a(n) = sum(k=3, n, if (ispolygonal(n, k), k));

Formula

a(n) >= n.

For m in A090466, a(m) > m.

For m in A090467, a(m) = m.