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 A131640 First differences are periodic: 50, 50, 75, 50, 50, 75, ... 1
 985, 1035, 1085, 1160, 1210, 1260, 1335, 1385, 1435, 1510, 1560, 1610, 1685, 1735, 1785, 1860, 1910, 1960, 2035, 2085, 2135, 2210, 2260, 2310, 2385, 2435, 2485, 2560, 2610, 2660, 2735, 2785, 2835, 2910, 2960, 3010, 3085, 3135, 3185, 3260, 3310, 3360 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS Harvey P. Dale, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (1, 0, 1, -1). FORMULA a(n) = 910 + Sum_{k=0..n}{25/9*[4*(k mod 3)+7*((k+1) mod 3)+10*((k+2) mod 3)]}. - Paolo P. Lava, Sep 26 2007 G.f.: -5*(-197-10*x-10*x^2+182*x^3)/((-1+x)^2*(x^2+x+1)). - R. J. Mathar, Nov 14 2007 MAPLE A131640 := proc(n) option remember ; if n =0 then 985 ; elif n mod 3 = 0 then A131640(n-1)+75 ; else A131640(n-1)+50 ; fi ; end: seq(A131640(n), n=0..80) ; # R. J. Mathar, Oct 24 2007 MATHEMATICA LinearRecurrence[{1, 0, 1, -1}, {985, 1035, 1085, 1160}, 50] (* Ray Chandler, Aug 25 2015 *) PROG Vec(-5*(-197-10*x-10*x^2+182*x^3)/((-1+x)^2*(x^2+x+1)) + O(x^40)) \\ Andrew Howroyd, Feb 20 2018 CROSSREFS Sequence in context: A294183 A288840 A289417 * A333443 A183718 A163025 Adjacent sequences:  A131637 A131638 A131639 * A131641 A131642 A131643 KEYWORD nonn,easy AUTHOR Eric M. Adler (eadler(AT)simi.k12.ca.us), Sep 05 2007 EXTENSIONS Definition supplied by N. J. A. Sloane, Sep 14 2007 More terms from R. J. Mathar, Oct 24 2007 STATUS approved

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Last modified October 1 00:42 EDT 2020. Contains 337440 sequences. (Running on oeis4.)