[go: up one dir, main page]

login
A007460
Shifts left under OR-convolution with itself.
(Formerly M1752)
9
1, 1, 2, 7, 20, 58, 174, 519, 1550, 4634, 13884, 41616, 124824, 374390, 1123288, 3369297, 10107324, 30320434, 90961626, 272878138, 818632094, 2455888346, 7367661682, 22102935920, 66308767426, 198926187730, 596778527246, 1790335274112, 5371006016314
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. [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]
FORMULA
a(n) ~ c * 3^n, where c = 0.23477965293553321256228091184896942343087043274059369777596946751928557... . - Vaclav Kotesovec, Sep 11 2014
MAPLE
a:= proc(n) option remember; `if`(n=0, 1, add(
Bits[Or](a(i), a(n-1-i)), i=0..n-1))
end:
seq(a(n), n=0..35); # Alois P. Heinz, Jun 22 2012, revised, Jun 16 2018
MATHEMATICA
a[0]=1; a[1]=1; a[n_] := a[n] = Sum[BitOr[a[k], a[n-k-1]], {k, 0, n-1}]; Table[a[n], {n, 0, 30}] (* Jean-François Alcover, Sep 07 2012, after Alois P. Heinz *)
PROG
(Haskell)
import Data.Bits ((.|.))
a007460 n = a007460_list !! n
a007460_list = 1 : f [1, 1] where
f xs = x : f (x:xs) where
x = sum $ zipWith (.|.) xs $ tail $ reverse xs :: Integer
-- Reinhard Zumkeller, Dec 29 2012
CROSSREFS
Sequence in context: A027120 A094982 A292400 * A034899 A026124 A026153
KEYWORD
nonn,nice,eigen
STATUS
approved