OFFSET
0,3
COMMENTS
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 0..10000
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 arXiv version]
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(
Bits[And](a(i), a(n-1-i)), i=0..n-1))
end:
seq(a(n), n=0..80); # Alois P. Heinz, Jun 16 2018
MATHEMATICA
a[0]=1; a[1]=1; a[n_] := a[n] = Sum[BitAnd[a[k], a[n-k-1]], {k, 0, n-1}]; Table[a[n], {n, 0, 60}] (* Jean-François Alcover, Sep 07 2012 *)
PROG
(Haskell)
import Data.Bits ((.&.))
a007461 n = a007461_list !! n
a007461_list = 1 : f [1, 1] where
f xs = x : f (x:xs) where
x = sum $ zipWith (.&.) xs $ tail $ reverse xs :: Integer
-- Reinhard Zumkeller, Apr 02 2012
CROSSREFS
KEYWORD
nonn,nice,eigen
AUTHOR
STATUS
approved