A139328 Sums of rows of the triangle in A139325.

0, 3, 6, 10, 14, 19, 24, 30, 36, 45, 52, 60, 67, 76, 86, 96, 105, 117, 127, 138, 151, 162, 176, 189, 203, 216, 230, 246, 262, 277, 292, 308, 325, 343, 362, 376, 398, 417, 435, 451, 473, 491, 515, 535, 557, 579, 599, 622, 646, 668, 691, 712, 737, 764, 788, 815

Offset: 1

Author

Reinhard Zumkeller, Apr 14 2008

Keywords

• nonn

Comments

a(n) = Sum_{k=1..n} A139325(n,k).

Examples

			a(4) = #{3,5,7}+#{11,13}+#{17,19,23}+#{29,31} = 3+2+3+2 = 10:
..1 ...3 ...5 ...7 ... primes in first row = {3,5,7},
..9 ..11 ..13 ..15 ... primes in 2nd row = {11,13},
.17 ..19 ..21 ..23 ... primes in 3rd row = {17,19,23},
.25 ..27 ..29 ..31 ... primes in 4th row = {29,31}.
		

Crossrefs

Cf. A000720, A038107, A139325.

Formula

a(n) = A000720(2*n^2 - 1) - 1.