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A167581
The second left hand column of triangle A167580.
5
-1, 0, 28, 192, 880, 3328, 11200, 34816, 102144, 286720, 777216, 2048000, 5271552, 13303808, 33013760, 80740352, 194969600, 465567744, 1100742656, 2579496960, 5996806144, 13841203200, 31738298368, 72343355392, 163997286400
OFFSET
2,3
FORMULA
a(n) = 2^n*(2*n^3 - 9*n^2 + 10*n - 3)/12.
GF(z) = (4*z^2 + 8*z - 1)/(1-2*z)^4.
a(n) = 8*a(n-1) - 24*a(n-2) + 32*a(n-3) - 16*a(n-4)
a(n) - 7*a(n-1) + 18*a(n-2) - 20*a(n-3) + 8*a(n-4) = 1*2^(n-1)
MATHEMATICA
LinearRecurrence[{8, -24, 32, -16}, {-1, 0, 28, 192}, 30] (* Harvey P. Dale, Jan 22 2012 *)
CROSSREFS
Equals the second left hand column of triangle A167580.
Other left hand columns are A014480 A167582, A168305 and A168306.
Sequence in context: A222967 A263944 A079903 * A135826 A220152 A042526
KEYWORD
easy,sign
AUTHOR
Johannes W. Meijer, Nov 10 2009
EXTENSIONS
Formulae and links added by Johannes W. Meijer, Nov 23 2009
STATUS
approved