This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A154999 a(n)=7*a(n-1)+42*a(n-2), n>2 ; a(0)=1, a(1)=1, a(2)=13 . 2

%I

%S 1,1,13,133,1477,15925,173509,1883413,20471269,222402229,2416608901,

%T 26257155925,285297665317,3099884206069,33681691385797,

%U 365966976355477,3976399872691813,43205412115772725,469446679463465221

%N a(n)=7*a(n-1)+42*a(n-2), n>2 ; a(0)=1, a(1)=1, a(2)=13 .

%F a(n+1)=Sum_{k, 0<=k<=n}A154929(n,k)*6^(n-k).

%F a(n)=(19/434)*sqrt(217)*{[(7/2)+(1/2)*sqrt(217)]^(n-1)-[(7/2)-(1/2)*sqrt(217)]^(n-1)} +(1/2)*{[(7/2)+(1/2)*sqrt(217)]^(n-1)+[(7/2)-(1/2)*sqrt(217)]^(n-1)}+(6/7)*[C(2*n,n) mod 2], with n>=0 [From _Paolo P. Lava_, Jan 20 2009]

%K nonn

%O 0,3

%A _Philippe Deléham_, Jan 18 2009

%E More terms from _Philippe Deléham_, Jan 27 2009

%E Corrected by D. S. McNeil, Aug 20 2010

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 22 04:39 EDT 2019. Contains 322329 sequences. (Running on oeis4.)