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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A100674 a(1) = 1; a(n+1) = sum{k=1..n} a(GCD(k,a(n))). 0
1, 1, 2, 3, 5, 9, 8, 9, 10, 13, 10, 27, 24, 59, 14, 80, 127, 17, 144, 169, 43, 21, 84, 183, 32, 126, 184, 140, 441, 124, 44, 74, 32, 209, 204, 463, 36, 617, 38, 798, 1025, 1124, 62, 86, 105, 422, 46, 551, 774, 222, 157, 51, 476, 820, 1492, 81, 470, 186, 183, 78, 459, 884 (list; graph; refs; listen; history; internal format)
OFFSET

1,3

MAPLE

a[1]:=1: for n from 2 to 70 do b[n]:=[seq(a[gcd(k, a[n-1])], k=1..n-1)]: a[n]:=sum(b[n][j], j=1..nops(b[n])) od: seq(a[n], n=1..70);

MATHEMATICA

a[1] = 1; a[n_] := a[n] = Plus @@ a /@ GCD[Range[n - 1], a[n - 1]]; Table[ a[n], {n, 62}] (from Robert G. Wilson v Dec 09 2004)

CROSSREFS

Sequence in context: A069805 A123923 A045965 * A058314 A072735 A127149

Adjacent sequences:  A100671 A100672 A100673 * A100675 A100676 A100677

KEYWORD

nonn

AUTHOR

Leroy Quet Dec 06 2004

EXTENSIONS

More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu) and Robert G. Wilson v, Dec 09 2004

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 09:50 EST 2012. Contains 205904 sequences.