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A141014
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E.g.f. Sum_{d|M} (exp(d*x)-1)/d, M=15.
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3
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0, 4, 24, 260, 3528, 51332, 762744, 11406980, 170939688, 2563287812, 38445332184, 576660215300, 8649804864648, 129746582562692, 1946196290656824, 29192932133689220, 437893920912786408
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n) = sum_{d|15} d^(n-1) = 1+3^(n-1)+5^(n-1)+15^(n-1). G.f.: -4*x*(-1+18*x-79*x^2+90*x^3)/((x-1) * (15*x-1) * (3*x-1) * (5*x-1)). a(n) = 24*a(n-1) -158*a(n-2) +360*a(n-3) -225*a(n-4). - R. J. Mathar, Mar 05 2010
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MAPLE
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A141014 := proc(n) local d; add(d^(n-1), d=numtheory[divisors](15)) ; end proc: seq(A141014(n), n=1..20) ; # R. J. Mathar, Mar 05 2010
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MATHEMATICA
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CoefficientList[Series[-4 x (-1 + 18 x - 79 x^2 + 90 x^3)/((x-1) (15 x-1) (3 x-1) (5 x-1)), {x, 0, 40}], x] (* Vincenzo Librandi, Dec 13 2012 *)
LinearRecurrence[{24, -158, 360, -225}, {0, 4, 24, 260, 3528}, 20] (* Harvey P. Dale, May 18 2023 *)
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PROG
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(Magma) [0] cat [1+3^(n-1)+5^(n-1)+15^(n-1): n in [1..20]]; // Vincenzo Librandi, Dec 13 2012
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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