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 A133725 a(n) = Sum_{d|n} mu(n/d)*d*(3*d - 1)/2. 1
 1, 4, 11, 17, 34, 35, 69, 70, 105, 106, 175, 142, 246, 213, 284, 284, 424, 321, 531, 428, 570, 535, 781, 572, 890, 750, 963, 858, 1246, 860, 1425, 1144, 1430, 1288, 1716, 1290, 2034, 1611, 2004, 1720, 2500, 1722, 2751, 2150, 2580, 2365, 3289, 2296, 3507, 2690 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Previous name was: A054525 * A000326. LINKS Table of n, a(n) for n=1..50. FORMULA Möbius transform of the pentagonal numbers. G.f.: Sum_{k>=1} mu(k) * x^k * (1 + 2*x^k) / (1 - x^k)^3. - Ilya Gutkovskiy, Sep 17 2021 EXAMPLE a(4) = 17 = (0, -1, 0, 1) dot (1, 5, 12, 22) = (0, -5, 0, 22). MAPLE read("transforms") : A000326 := proc(n) n*(3*n-1)/2 ; end: a000326 := [seq(A000326(n), n=1..300)] ; a133725 := MOBIUS(a000326) ; for i from 1 to nops(a133725) do printf("%d, ", op(i, a133725)) ; od: # R. J. Mathar, Jan 19 2009 CROSSREFS Cf. A000326, A007434, A007438, A054525. Sequence in context: A063237 A026381 A063556 * A050395 A368424 A059771 Adjacent sequences: A133722 A133723 A133724 * A133726 A133727 A133728 KEYWORD nonn AUTHOR Gary W. Adamson, Sep 21 2007 EXTENSIONS More terms from R. J. Mathar, Jan 19 2009 New name from Ilya Gutkovskiy, Sep 17 2021 STATUS approved

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Last modified March 3 03:04 EST 2024. Contains 370499 sequences. (Running on oeis4.)