The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A238391 Expansion of (1+x)/(1-x^2-3*x^5). 2
 1, 1, 1, 1, 1, 4, 4, 7, 7, 10, 19, 22, 40, 43, 70, 100, 136, 220, 265, 430, 565, 838, 1225, 1633, 2515, 3328, 5029, 7003, 9928, 14548, 19912, 29635, 40921, 59419, 84565, 119155, 173470, 241918, 351727, 495613, 709192, 1016023, 1434946, 2071204, 2921785, 4198780, 5969854, 8503618, 12183466, 17268973, 24779806 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,6 LINKS Alois P. Heinz, Table of n, a(n) for n = 0..1000 [Terms 0 through 500 were computed by G. C. Greubel] Index entries for linear recurrences with constant coefficients, signature (0,1,0,0,3). FORMULA a(0)=1, a(1)=1, a(2)=1, a(3)=1, a(4)=1; a(n) = 3*a(n-5)+a(n-2) for n>4. a(2n) = Sum_{j=0..n/5} binomial(n-3j,2j)*3^(2j) + Sum_{j=0..(n-3)/5} binomial(n-2-3j,2j+1)*3^(2j+1). a(2n+1) = Sum_{j=0..n/5} binomial(n-3j,2j)*3^{2j} + Sum_{j=0..(n-2)/5} binomial(n-1-3j,2j+1)*3^(2j+1). EXAMPLE a(5) = 3*a(0)+a(3)=4; a(6) = 3*a(1)+a(4)=4; a(7) = 3*a(2)+a(5)=7. MATHEMATICA For[j = 0, j < 5, j++, a[j] = 1]; For[j = 5, j < 51, j++, a[j] = 3 a[j - 5] + a[j - 2]]; Table[a[j], {j, 0, 50}] CoefficientList[Series[(1 + x)/(1 - x^2 - 3 x^5), {x, 0, 50}], x] (* Michael De Vlieger, Jan 27 2016 *) PROG (PARI) Vec((1+x)/(1-x^2-3*x^5) + O(x^50)) \\ Michel Marcus, Jan 27 2016 CROSSREFS Sequence in context: A200364 A147814 A168233 * A049647 A263619 A046538 Adjacent sequences:  A238388 A238389 A238390 * A238392 A238393 A238394 KEYWORD nonn,easy AUTHOR Sergio Falcon, Feb 26 2014 STATUS approved

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

Last modified May 24 17:53 EDT 2022. Contains 354043 sequences. (Running on oeis4.)