cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A281611 Expansion of Sum_{p prime, i>=2} x^(p^i)/(1 - x^(p^i)) / Product_{j>=1} (1 - x^j).

Original entry on oeis.org

0, 0, 0, 1, 1, 2, 3, 7, 10, 16, 23, 36, 50, 73, 100, 144, 193, 267, 355, 481, 631, 838, 1088, 1426, 1833, 2368, 3019, 3861, 4879, 6178, 7751, 9737, 12131, 15120, 18721, 23181, 28535, 35110, 42991, 52606, 64090, 78015, 94609, 114621, 138398, 166927, 200737, 241131, 288864, 345649, 412592, 491931
Offset: 1

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Author

Ilya Gutkovskiy, Jan 25 2017

Keywords

Comments

Total number of proper prime power parts (A246547) in all partitions of n.

Examples

			a(6) = 2 because we have [6], [5, 1], [4, 2], [4, 1, 1], [3, 3], [3, 2, 1], [3, 1, 1, 1], [2, 2, 2], [2, 1, 1, 1, 1], [1, 1, 1, 1, 1, 1] and 0 + 0 + 1 + 1 + 0 + 0 + 0 + 0 + 0 + 0 + 0 = 2.
		

Crossrefs

Programs

  • Mathematica
    nmax = 52; Rest[CoefficientList[Series[Sum[Sign[PrimeOmega[i] - 1] Floor[1/PrimeNu[i]] x^i/(1 - x^i), {i, 2, nmax}]/Product[1 - x^j, {j, 1, nmax}], {x, 0, nmax}], x]]

Formula

G.f.: Sum_{p prime, i>=2} x^(p^i)/(1 - x^(p^i)) / Product_{j>=1} (1 - x^j).
a(n) = A073335(n) - A037032(n).