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A108115 Let B(x) = Sum_{i >= 0} A108336(i)*x^i; sequence gives coefficients of B(x)^2. 1
1, 2, 1, 2, 2, 2, 5, 2, 2, 2, 1, 2, 1, 2, 2, 2, 6, 2, 6, 6, 2, 6, 2, 2, 2, 2, 5, 2, 6, 6, 5, 14, 5, 6, 6, 2, 5, 2, 2, 2, 2, 6, 2, 6, 6, 2, 6, 2, 2, 2, 1, 2, 1, 2, 2, 2, 5, 2, 2, 2, 1, 2, 1, 2, 2, 2, 6, 2, 6, 6, 2, 6, 2, 2, 2, 2, 6, 2, 6, 6, 6, 14, 6, 10, 6, 6, 10, 6, 14, 10, 10, 18, 10, 18, 10, 10, 14 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Robert Israel, Table of n, a(n) for n = 0..10000

MAPLE

S:= 0: SS:= 0:

for i from 0 to 100 do

  s:= coeff(SS, x, i) mod 4;

  if s = 0 or s = 3 then

     SS:= SS + 2*expand(S*x^i)+x^(2*i); S:= S + x^i;

  fi

od:

seq(coeff(SS, x, i), i=0..100); # Robert Israel, May 14 2019

CROSSREFS

Cf. A108336.

a(n) mod 4 = A083952(n).

Sequence in context: A113401 A071227 A285442 * A089254 A279861 A321431

Adjacent sequences:  A108112 A108113 A108114 * A108116 A108117 A108118

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Jul 03 2005

STATUS

approved

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Last modified February 26 12:43 EST 2020. Contains 332280 sequences. (Running on oeis4.)