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

1,2

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.

Links

Table of n, a(n) for n=1..52.

Formula

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

Example

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

Crossrefs

Cf. A000452.

Sequence in context: A125627 A332410 A194142 * A178419 A065504 A071619

Adjacent sequences: A174645 A174646 A174647 * A174649 A174650 A174651

Keyword

nonn

Author

Jonathan Vos Post, Mar 25 2010

Status

approved