login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A117719 a(2n) = A001653(n) (Numbers n such that 2*n^2 - 1 is a square), a(2n+1) = A038725(n+1). 0
1, 2, 5, 11, 29, 64, 169, 373, 985, 2174, 5741, 12671, 33461, 73852, 195025, 430441, 1136689, 2508794, 6625109, 14622323, 38613965, 85225144, 225058681, 496728541, 1311738121, 2895146102, 7645370045, 16874148071, 44560482149 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

FORMULA

G.f. (1+2*x-x^2-x^3)/((x^2+2*x-1)*(x^2-2*x-1))

CROSSREFS

Cf. A001653, A038725.

Sequence in context: A202476 A127331 A040998 * A192785 A014211 A160911

Adjacent sequences:  A117716 A117717 A117718 * A117720 A117721 A117722

KEYWORD

nonn

AUTHOR

Creighton Dement (creighton.k.dement(AT)uni-oldenburg.de), Apr 13 2006

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 .

Last modified February 16 21:51 EST 2012. Contains 205978 sequences.