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 A131081 Periodic sequence (8, 7, 4, 1, 0, 1, 4, 7). 5
 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8, 7, 4, 1, 0, 1, 4, 7, 8 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Fourth column of triangular array T defined in A131074. LINKS Index entries for linear recurrences with constant coefficients, signature (1,0,0,-1,1). FORMULA a(1) = 8, a(2) = a(8) = 7, a(3) = a(7) = 4, a(4) = a(6) = 1, a(5) = 0; for n > 8, a(n) = a(n-8). G.f.: (8-x-3*x^2-3*x^3+7*x^4)/((1-x)*(1+x^4)). a(n)=1/56*{(n mod 8)-13*[(n+1) mod 8]-13*[(n+2) mod 8]+[(n+3) mod 8]+15*[(n+4) mod 8]+29*[(n+5) mod 8]+29*[(n+6) mod 8]+15*[(n+7) mod 8]}, with n>=0. - Paolo P. Lava, Jun 19 2007 MATHEMATICA PadRight[{}, 120, {8, 7, 4, 1, 0, 1, 4, 7}]  Harvey P. Dale, May 20 2012 PROG (PARI) {m=105; for(n=1, m, r=(n-1)%8; print1(if(r==0, 8, if(r==1||r==7, 7, if(r==2||r==6, 4, if(r==4, 0, 1)))), ", "))} (MAGMA) m:=105; [ [8, 7, 4, 1, 0, 1, 4, 7][(n-1) mod 8 + 1]: n in [1..m] ]; CROSSREFS Cf. A131074, A131028. Sequence in context: A086253 A225119 A094883 * A158288 A193716 A268046 Adjacent sequences:  A131078 A131079 A131080 * A131082 A131083 A131084 KEYWORD nonn,easy,less AUTHOR Klaus Brockhaus, following a suggestion of Paul Curtz, Jun 14 2007 STATUS approved

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Last modified December 13 15:03 EST 2018. Contains 318086 sequences. (Running on oeis4.)