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 A094825 Number of (s(0), s(1), ..., s(2n)) such that 0 < s(i) < 10 and |s(i) - s(i-1)| = 1 for i = 1,2,....,2n, s(0) = 1, s(2n) = 7. 3
 1, 7, 35, 153, 624, 2444, 9333, 35055, 130207, 479941, 1759616, 6427032, 23412105, 85121783, 309062619, 1121050449, 4063463728, 14721293860, 53313308477, 193023319071, 698715633111, 2528895064637, 9152032060800, 33118656195888 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,2 LINKS Michael De Vlieger, Table of n, a(n) for n = 3..1792 László Németh and László Szalay, Sequences Involving Square Zig-Zag Shapes, J. Int. Seq., Vol. 24 (2021), Article 21.5.2. Index entries for linear recurrences with constant coefficients, signature (8,-21,20,-5) FORMULA a(n)=(1/5)*Sum(r, 1, 9, Sin(r*Pi/10)Sin(7*r*Pi/10)(2Cos(r*Pi/10))^(2n)). a(n)=8a(n-1)-21a(n-2)+20a(n-3)-5a(n-4). G.f.: x^3*(1-x)/( (1-3*x+x^2)*(1-5*x+5*x^2) ). a(n) = -A001906(n)/2 + A020876(n)/10. - R. J. Mathar, Jun 24 2011 MATHEMATICA LinearRecurrence[{8, -21, 20, -5}, {1, 7, 35, 153}, 30] (* Harvey P. Dale, Jan 16 2015 *) CROSSREFS Cf. A094865 (partial sums). Sequence in context: A223621 A215510 A240423 * A022635 A336602 A217274 Adjacent sequences:  A094822 A094823 A094824 * A094826 A094827 A094828 KEYWORD nonn AUTHOR Herbert Kociemba, Jun 15 2004 STATUS approved

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Last modified January 28 04:30 EST 2022. Contains 350654 sequences. (Running on oeis4.)