|
|
A007464
|
|
Shifts left under GCD-convolution with itself.
(Formerly M0536)
|
|
9
|
|
|
1, 1, 2, 3, 4, 6, 6, 11, 10, 18, 16, 20, 24, 26, 20, 45, 40, 38, 34, 62, 46, 54, 50, 84, 50, 102, 78, 104, 98, 90, 70, 189, 82, 130, 84, 120, 112, 130, 120, 232, 152, 234, 132, 130, 208, 282, 140, 462, 180, 210, 220, 418, 284, 334, 260, 520, 156, 334, 556
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
REFERENCES
|
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
|
|
LINKS
|
M. Bernstein and N. J. A. Sloane, Some canonical sequences of integers, Linear Alg. Applications, 226-228 (1995), 57-72; erratum 320 (2000), 210; arXiv:math/0205301 [math.CO], 2002.
M. Bernstein and N. J. A. Sloane, Some canonical sequences of integers, Linear Alg. Applications, 226-228 (1995), 57-72; erratum 320 (2000), 210. [Link to Lin. Alg. Applic. version together with omitted figures]
|
|
MAPLE
|
a:= proc(n) option remember;
`if`(n=0, 1, add(igcd(a(i), a(n-1-i)), i=0..n-1))
end:
|
|
MATHEMATICA
|
|
|
PROG
|
(PARI) N=66; v=vector(N); v[1]=1; for(n=2, N, v[n]=sum(k=1, n-1, gcd(v[k], v[n-k])) ); v \\ Joerg Arndt, Jun 30 2013
(Haskell)
a007464 n = a007464_list !! n
a007464_list = 1 : 1 : f [1, 1] where
f xs = y : f (y:xs) where y = sum $ zipWith gcd xs $ reverse xs
(Python)
from fractions import gcd
for n in range(1, 10**3):
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,nice,eigen
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|