A174648 Partial sums of A000452.

1, 3, 6, 11, 17, 24, 32, 42, 53, 66, 80, 95, 111, 128, 147, 168, 190, 213, 237, 263, 290, 319, 349, 380, 413, 447, 482, 519, 557, 596, 636, 677, 719, 762, 808, 855, 903, 954, 1007, 1061, 1116, 1172, 1229, 1287, 1346, 1407, 1469, 1534, 1600, 1667, 1736, 1806

Offset: 1

Author

Jonathan Vos Post, Mar 25 2010

Keywords

• nonn

Comments

Partial sums of sequence starting with a(1) = 1 and for which a(n) is smallest number which avoids any 3-term G.P. (geometric progression). The subsequence of primes in this partial sum begins: 3, 11, 17, 53, 263, 349, 557, 677, 719, 1061, 1229, 1667, 1877, 2179, 3019, 3203. The subsequence of squares begins: 1, 1600. subsequence of powers of 2 begins: 1, 32, 128.

Examples

			a(9) = 1 + 2 + 3 + 5 + 6 + 7 + 8 + 10 + 11 = 53 is prime.
		

Crossrefs

Cf. A000452.

Formula

a(n) = Sum_{i=1..n} A000452(i).