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 A137798 Partial sums of A137797. 1
 0, 0, 4, 8, 16, 14, 16, 18, 24, 30, 30, 30, 34, 38, 46, 44, 46, 48, 54, 60, 60, 60, 64, 68, 76, 74, 76, 78, 84, 90, 90, 90, 94, 98, 106, 104, 106, 108, 114, 120, 120, 120, 124, 128, 136, 134, 136, 138, 144, 150, 150, 150, 154, 158, 166, 164, 166, 168, 174, 180, 180, 180 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Table of n, a(n) for n=0..61. Index entries for linear recurrences with constant coefficients, signature (0,1,0,0,1,0,-1). FORMULA f(n) = Sum{k=0,n} 2*((k+1) mod 5) - 2*((k+1) mod 2). a(n) = a(n-2)+a(n-5)-a(n-7) for n>6. - Colin Barker, Dec 16 2014 G.f.: 2*x^2*(3*x^3+6*x^2+4*x+2) / ((x-1)^2*(x+1)*(x^4+x^3+x^2+x+1)). - Colin Barker, Dec 16 2014 MATHEMATICA Accumulate[LinearRecurrence[{-1, 0, 0, 0, 1, 1}, {0, 0, 4, 4, 8, -2, 2}, 100]] (* or *) LinearRecurrence[{0, 1, 0, 0, 1, 0, -1}, {0, 0, 4, 8, 16, 14, 16}, 100] (* Harvey P. Dale, Jun 08 2015 *) PROG (Python) sequence = [] l = list(range(20)) while len(l) > 0: a = l.pop(0) z = sum(2*((x+1)%5)-2*((x+1)%2) for x in range(a)) sequence.append(z) print(sequence) (PARI) concat([0, 0], Vec(2*x^2*(3*x^3+6*x^2+4*x+2)/((x-1)^2*(x+1)*(x^4+x^3+x^2+x+1)) + O(x^100))) \\ Colin Barker, Dec 16 2014 CROSSREFS Cf. A137797. Sequence in context: A110652 A354778 A059373 * A312754 A312755 A312756 Adjacent sequences: A137795 A137796 A137797 * A137799 A137800 A137801 KEYWORD easy,nonn AUTHOR William A. Tedeschi, Feb 10 2008 STATUS approved

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Last modified June 19 09:37 EDT 2024. Contains 373501 sequences. (Running on oeis4.)