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

 

Logo

Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A007462 Shifts left under XOR-convolution with itself.
(Formerly M1274)
3
0, 1, 2, 4, 14, 38, 118, 338, 1006, 2990, 8974, 26862, 80510, 241390, 723934, 2171046, 6512910, 19536974, 58608782, 175821710, 527470318, 1582385678, 4747139342, 14241362318, 42724100334, 128172182990, 384516408110, 1153548740206, 3460645850030, 10381936700110 (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

Alois P. Heinz, Table of n, a(n) for n = 0..1000

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 = 0.151273188266276362886260408769663538575624024971525940842364624... . - Vaclav Kotesovec, Sep 10 2014

MAPLE

with(Bits):

a:= proc(n) option remember;

      `if`(n<2, n, add(Xor(a(i), a(n-1-i)), i=0..n-1))

    end:

seq(a(n), n=0..30);  # Alois P. Heinz, Jun 22 2012

MATHEMATICA

a[0]=0; a[1]=1; a[n_] := a[n] = Sum[BitXor[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 (xor)

a007462 n = a007462_list !! n

a007462_list = 0 : 1 : f [1, 0] where

   f xs = y : f (y : xs) where

     y = sum $ zipWith xor xs $ reverse xs :: Integer

-- Reinhard Zumkeller, Jul 15 2012

CROSSREFS

Cf. A192484, A199770.

Sequence in context: A135960 A216630 A006611 * A053623 A035010 A055540

Adjacent sequences:  A007459 A007460 A007461 * A007463 A007464 A007465

KEYWORD

nonn,nice,eigen

AUTHOR

N. J. A. Sloane

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 12 16:38 EST 2017. Contains 295949 sequences.