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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A090407 a(n) = Sum_{k = 0..n} C(4*n + 1, 4*k). 4

%I #16 Feb 06 2019 12:59:45

%S 1,6,136,2016,32896,523776,8390656,134209536,2147516416,34359607296,

%T 549756338176,8796090925056,140737496743936,2251799780130816,

%U 36028797153181696,576460751766552576,9223372039002259456

%N a(n) = Sum_{k = 0..n} C(4*n + 1, 4*k).

%H Harvey P. Dale, <a href="/A090407/b090407.txt">Table of n, a(n) for n = 0..800</a>

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (12,64).

%F From _Harvey P. Dale_, Jan 19 2012: (Start)

%F a(0) = 1, a(1) = 6, a(n) = 12*a(n-1)+64*a(n-2).

%F G.f.: (6*x-1)/(64*x^2+12*x-1). (End)

%F a(n) = (1/2) * 4^n * (4^n + (-1)^n). - _Peter Bala_, Feb 06 2019

%t Table[Sum[Binomial[4n+1,4k],{k,0,n}],{n,0,30}] (* or *) LinearRecurrence[ {12,64},{1,6},30] (* _Harvey P. Dale_, Jan 19 2012 *)

%Y Cf. A070775, A001025, A090408, A038503.

%K easy,nonn

%O 0,2

%A _Paul Barry_, Nov 29 2003

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 19 23:40 EDT 2024. Contains 371798 sequences. (Running on oeis4.)