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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

Table of n, a(n) for n=1..66.

Index entries for related partition-counting sequences

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.)