This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A107247 Sum of squares of nonacci numbers (Fibonacci 9-step numbers). 1

%I

%S 0,0,0,0,0,0,0,1,2,6,22,86,342,1366,5462,21846,87382,348503,1390944,

%T 5552544,22166320,88491056,353269040,1410299184,5630100784,

%U 22476064048,89727075632,358201316657,1429983219018,5708667195022,22789694921422

%N Sum of squares of nonacci numbers (Fibonacci 9-step numbers).

%C Primes in this sequence include: a(9) = 2, which is next? Semiprimes in this sequence include: a(10) = 6 = 2 * 3, a(11) = 22 = 2 * 11, a(12) = 86 = 2 * 43, a(14) = 1366 = 2 * 683, a(15) = 5462 = 2 * 2731, a(17) = 87382 = 2 * 43691, a(18) = 348503 = 37 * 9419, a(28) = 358201316657 = 71 * 5045088967.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Fibonaccin-StepNumber.html">Fibonacci n-Step Number</a>.

%F a(n) = F_9(0)^2 + F_9(1)^2 + ... F_9(n)^2, where F_9(n) = A104144(n).

%Y Cf. A104144, A107239-A107246, A107248.

%K easy,nonn

%O 0,9

%A _Jonathan Vos Post_, May 29 2005

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .