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A024403
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[ (4th elementary symmetric function of S(n))/(3rd elementary symmetric function of S(n)) ], where S(n) = {first n+3 positive integers congruent to 2 mod 3}.
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1
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1, 3, 5, 9, 13, 18, 24, 30, 37, 45, 54, 64, 74, 85, 97, 109, 122, 136, 151, 167, 183, 200, 218, 236, 255, 275, 296, 318, 340, 363, 387, 411, 436, 462, 489, 517, 545, 574, 604, 634, 665, 697, 730, 764, 798, 833, 869, 905, 942, 980, 1019, 1059, 1099, 1140, 1182, 1224
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OFFSET
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1,2
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LINKS
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Vincenzo Librandi, Table of n, a(n) for n = 1..5000
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FORMULA
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Empirical g.f.: x*(x^2-x+1)*(x^8-x^7-x^5+x^4-x^3-x-1) / ((x-1)^3*(x^2+1)*(x^4+1)). - Colin Barker, Aug 16 2014
a(n) = floor(A024393(n) / A024392(n + 1)). - Sean A. Irvine, Jul 07 2019
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MATHEMATICA
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Table[Floor[(n (405 n^4 + 4590 n^3 + 18495 n^2 + 30534 n + 16376)) / (40 (3 n + 10) (9 (n+1)^2 + 33 n + 55))], {n, 1, 100}] (* Vincenzo Librandi, Jul 07 2019 *)
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PROG
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(MAGMA) [(n*(405*n^4+4590*n^3+18495*n^2+30534*n+16376)) div (40*(3*n+10)*(9*(n+1)^2+33*n+55)): n in [1..60]]; // Vincenzo Librandi, Jul 07 2019
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CROSSREFS
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Cf. A024392, A024393.
Sequence in context: A260733 A265429 A122248 * A129230 A203567 A071404
Adjacent sequences: A024400 A024401 A024402 * A024404 A024405 A024406
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KEYWORD
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nonn
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AUTHOR
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Clark Kimberling
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STATUS
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approved
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