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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A129090 a(1)=1. a(n) = GCD(a(n-1),n) + LCM(a(n-1),n). 1
1, 3, 6, 14, 71, 427, 434, 1738, 15643, 156431, 156442, 938654, 12202503, 170835043, 2562525646, 20500205170, 348503487891, 2091020927349, 39729397619632, 198646988098164, 1390528916687151, 30591636167117323, 703607631843698430 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

MAPLE

a[1]:=1: for n from 2 to 30 do a[n]:=gcd(a[n-1], n)+lcm(a[n-1], n) od: seq(a[n], n=1..27); - Emeric Deutsch (deutsch(AT)duke.poly.edu), Apr 13 2007

MATHEMATICA

k = 1; Do[Print[k]; k = GCD[k, n] + LCM[k, n], {n, 2, 30}] - Ryan Propper (rpropper(AT)stanford.edu), Apr 07 2007

CROSSREFS

Cf. A129091.

Sequence in context: A101162 A059741 A054099 * A058141 A144654 A132279

Adjacent sequences:  A129087 A129088 A129089 * A129091 A129092 A129093

KEYWORD

nonn

AUTHOR

Leroy Quet Mar 29 2007

EXTENSIONS

More terms from Ryan Propper (rpropper(AT)stanford.edu) and Emeric Deutsch (deutsch(AT)duke.poly.edu), Apr 07 2007

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.