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!)
 A304940 Expansion of ((1 + 4*x)/(1 - 4*x))^(1/2). 2
 1, 4, 8, 32, 96, 384, 1280, 5120, 17920, 71680, 258048, 1032192, 3784704, 15138816, 56229888, 224919552, 843448320, 3373793280, 12745441280, 50981765120, 193730707456, 774922829824, 2958796259328, 11835185037312, 45368209309696, 181472837238784 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Let ((1 + k*x)/(1 - k*x))^(m/k) = a(0) + a(1)*x + a(2)*x^2 + ... Then n*a(n) = 2*m*a(n-1) + k^2*(n-2)*a(n-2) for n > 1. LINKS Seiichi Manyama, Table of n, a(n) for n = 0..1000 FORMULA n*a(n) = 4*a(n-1) + 4^2*(n-2)*a(n-2) for n > 1. a(n) = 2^n * A063886(n). PROG (PARI) N=66; x='x+O('x^N); Vec(((1+4*x)/(1-4*x))^(1/2)) CROSSREFS ((1 + 4*x)/(1 - 4*x))^(m/4): A303537 (m=1), this sequence (m=2), A304941 (m=3), A081654 (m=4). Cf. A063886. Sequence in context: A086344 A209084 A254216 * A068205 A241684 A254878 Adjacent sequences:  A304937 A304938 A304939 * A304941 A304942 A304943 KEYWORD nonn AUTHOR Seiichi Manyama, May 22 2018 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 August 15 01:28 EDT 2020. Contains 336484 sequences. (Running on oeis4.)