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A007461 Shifts left under AND-convolution with itself.
(Formerly M0117)
4
1, 1, 2, 1, 2, 4, 0, 5, 2, 4, 0, 10, 0, 12, 4, 13, 6, 12, 0, 18, 12, 20, 20, 36, 20, 36, 16, 44, 32, 60, 40, 73, 50, 56, 40, 58, 44, 52, 60, 84, 36, 112, 88, 108, 136, 132, 152, 178, 136, 232, 108, 260, 244, 256, 304, 288 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

a(A000225(n)) mod 2 = 1, a(A062289(n)) mod 2 = 0. [Reinhard Zumkeller, Apr 02 2012]

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]

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-Fran├žois 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

Sequence in context: A265255 A131022 A137408 * A181302 A143446 A110330

Adjacent sequences:  A007458 A007459 A007460 * A007462 A007463 A007464

KEYWORD

nonn,nice,eigen

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified June 22 12:24 EDT 2017. Contains 288613 sequences.