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 A281668 Expansion of Sum_{p prime, i>=1} x^(p^i)/(1 + x^(p^i)) * Product_{p prime, j>=1} (1 + x^(p^j)). 1
 0, 1, 1, 1, 3, 2, 5, 3, 8, 7, 10, 12, 13, 20, 18, 26, 25, 36, 34, 45, 47, 59, 62, 71, 82, 91, 105, 112, 132, 143, 163, 174, 201, 220, 244, 266, 298, 327, 362, 388, 437, 470, 521, 558, 621, 671, 733, 788, 864, 938, 1011, 1100, 1182, 1295, 1379, 1501, 1606, 1753, 1861, 2017, 2158, 2335, 2493, 2672, 2871, 3078 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 COMMENTS Total number of parts in all partitions of n into distinct prime power parts (1 excluded). LINKS FORMULA G.f.: Sum_{p prime, i>=1} x^(p^i)/(1 + x^(p^i)) * Product_{p prime, j>=1} (1 + x^(p^j)). EXAMPLE a(10) = 7 because we have [8, 2], [7, 3], [5, 3, 2] and 2 + 2 + 3 = 7. MATHEMATICA nmax = 66; Rest[CoefficientList[Series[Sum[Floor[1/PrimeNu[i]] x^i/(1 + x^i), {i, 2, nmax}] Product[1 + Floor[1/PrimeNu[j]] x^j, {j, 2, nmax}], {x, 0, nmax}], x]] CROSSREFS Cf. A015723, A024938, A054685, A246655, A281616. Sequence in context: A181771 A238628 A045766 * A132817 A131025 A340702 Adjacent sequences: A281665 A281666 A281667 * A281669 A281670 A281671 KEYWORD nonn AUTHOR Ilya Gutkovskiy, Jan 26 2017 STATUS approved

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Last modified January 27 08:42 EST 2023. Contains 359838 sequences. (Running on oeis4.)