Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A077138
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A077138 a(1) = 1, then if n is even multiply it by the previous term else add to get the next term. +0
2
0, 1, 2, 5, 20, 25, 150, 157, 1256, 1265, 12650, 12661, 151932, 151945, 2127230, 2127245, 34035920, 34035937, 612646866, 612646885, 12252937700, 12252937721, 269564629862, 269564629885, 6469551117240, 6469551117265, 168208329048890 (list; graph; listen)
OFFSET

0,3

FORMULA

a(1) = 1, a(2n) = 2n*a(2n-1) and a(2n+1) = a(2n) +(2n +1).

PROGRAM

(PARI) a(n)=if(n<0, 0, if(n%2, n+a(n-1), n*a(n-1)))

CROSSREFS

Cf. A047905.

Sequence in context: A059079 A136900 A136898 this_sequence A056726 A136899 A136882

Adjacent sequences: A077135 A077136 A077137 this_sequence A077139 A077140 A077141

KEYWORD

nonn

AUTHOR

Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Oct 30 2002

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 16 17:18 EST 2009. Contains 170825 sequences.


AT&T Labs Research