The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A047557 Numbers that are congruent to {0, 3, 6, 7} mod 8. 4
 0, 3, 6, 7, 8, 11, 14, 15, 16, 19, 22, 23, 24, 27, 30, 31, 32, 35, 38, 39, 40, 43, 46, 47, 48, 51, 54, 55, 56, 59, 62, 63, 64, 67, 70, 71, 72, 75, 78, 79, 80, 83, 86, 87, 88, 91, 94, 95, 96, 99, 102, 103, 104, 107, 110, 111, 112, 115, 118, 119, 120, 123, 126 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Index entries for linear recurrences with constant coefficients, signature (2,-2,2,-1). FORMULA From R. J. Mathar, Oct 08 2011: (Start) G.f.: x^2*(3+x^2) / ( (x^2+1)*(x-1)^2 ). a(n) = 2*n-1-sin(Pi*n/2). (End) a(n) = 2n-1-cos(Pi*(n-1)/2). - Wesley Ivan Hurt, Oct 22 2013 From Wesley Ivan Hurt, May 20 2016: (Start) a(n) = 2*a(n-1)-2*a(n-2)+2*a(n-3)-a(n-4) for n>4. a(n) = 2*n-2-I^(1-n)*(I^(n-1)-1)^2/2 where I=sqrt(-1). a(2n) = A004767(n-1) for n>0, a(2n-1) = A047451(n). (End) MAPLE A047557:=n->2*n-1-cos(Pi*(n-1)/2): seq(A047557(k), k=1..100); # Wesley Ivan Hurt, Oct 22 2013 MATHEMATICA Table[2n-1-Cos[Pi(n-1)/2], {n, 100}] (* Wesley Ivan Hurt, Oct 22 2013 *) PROG (Sage) [lucas_number1(n, 0, 1)+2*n+3 for n in range(-1, 55)] # Zerinvary Lajos, Jul 06 2008 CROSSREFS Cf. A004767, A047404, A047431, A047451, A047546, A047578, A056594. Sequence in context: A206586 A289176 A277851 * A342736 A284390 A099850 Adjacent sequences:  A047554 A047555 A047556 * A047558 A047559 A047560 KEYWORD nonn,easy AUTHOR EXTENSIONS More terms from Wesley Ivan Hurt, May 20 2016 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 19 09:12 EDT 2021. Contains 343110 sequences. (Running on oeis4.)