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A174648
Partial sums of A000452.
0
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.
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
KEYWORD
nonn
AUTHOR
Jonathan Vos Post, Mar 25 2010
STATUS
approved