login
A103646
G.f.: 9*(3x+1)/(1+2x-6x^2-27x^3).
1
9, 9, 36, 225, 9, 2304, 1521, 11025, 49284, 8649, 576081, 230400, 3229209, 10478169, 4639716, 140778225, 29192409, 911556864, 2153052801, 1951430625, 33627490884, 2586027609, 249281516961, 424895385600, 715721076009, 7848531119529
OFFSET
0,1
COMMENTS
A floretion-generated sequence of squares. This sequence is related to several other sequences of squares.
Floretion Algebra Multiplication Program, FAMP Code: 4ibaseiseq[ x*(+ 'i + 'j + i' + j' + 'ii' + 'jj' + 'ij' + 'ji' + e) ] where x is the sum of all (16) floretion basis vectors.
FORMULA
a(n+3) = -2a(n+2) + 6a(n+1) + 27a(n), a(0) = 9, a(1) = 9, a(2) = 36
a(n) = 9*A103644(n).
4*3^(n+1) = 2*A103644(n) + a(n) + A103645(n) = 11*A103644(n) + A103645(n).
a(n) = A110523(n+2)^2. - R. J. Mathar, Sep 11 2019
MATHEMATICA
CoefficientList[ Series[9(3x + 1)/(1 + 2x - 6x^2 - 27x^3), {x, 0, 25}], x] (* Robert G. Wilson v, Feb 12 2005 *)
LinearRecurrence[{-2, 6, 27}, {9, 9, 36}, 40] (* Harvey P. Dale, Mar 14 2016 *)
CROSSREFS
Sequence in context: A339735 A341835 A097988 * A246314 A341538 A325895
KEYWORD
easy,nonn
AUTHOR
Creighton Dement, Feb 12 2005
EXTENSIONS
Corrected and extended by Robert G. Wilson v, Feb 12 2005
STATUS
approved