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 A174226 Partial sums of A034897. 0
 6, 27, 55, 356, 681, 1177, 1874, 3207, 5116, 7157, 9290, 13191, 21319, 32012, 48525, 68046, 92647, 119624, 170925, 267286, 397439, 557280, 720481, 897142, 1111415, 1361736, 1637569, 1933910, 2240091, 2629684, 3116561, 3612090, 4154503 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Partial sums of hyperperfect numbers. The subsequence of prime values in this partial sum begins: 21319, 92647, 720481. LINKS FORMULA a(n) = SUM[i=1..n] A034897(i) = SUM[i=1..n] {m such that k*sigma(m) = (k+1)*m + k - 1 for some positive integer k, and sigma being the divisor function A000005; noting that k=1 gives perfect numbers}. EXAMPLE a(x) = 6 + 21 + 28 + 301 + 325 + 496 + 697 + 1333 + 1909 + 2041 + 2133 + 3901 + 8128 + 10693 + 16513 + 19521 + 24601 = 92647 is prime. CROSSREFS Cf. A034897, A034898, A007592, A019279. Sequence in context: A183603 A067876 A309337 * A100784 A174974 A273578 Adjacent sequences:  A174223 A174224 A174225 * A174227 A174228 A174229 KEYWORD nonn AUTHOR Jonathan Vos Post, Mar 12 2010 STATUS approved

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Last modified April 13 06:02 EDT 2021. Contains 342935 sequences. (Running on oeis4.)