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A394307
Number of induced cubes in the n X n zebra graph.
0
1, 4, 9, 24, 49, 88, 151, 236, 351, 496, 672, 880, 1120, 1392, 1696, 2032, 2400, 2800, 3232, 3696, 4192, 4720, 5280, 5872, 6496, 7152, 7840, 8560, 9312, 10096, 10912, 11760, 12640, 13552, 14496, 15472, 16480, 17520, 18592, 19696, 20832, 22000, 23200, 24432
OFFSET
1,2
LINKS
Eric Weisstein's World of Mathematics, Cube Polynomial.
Eric Weisstein's World of Mathematics, Zebra Graph.
FORMULA
a(n)=16*(n^2-10*n+31) for n > 9.
a(n) = 3*a(n-1)-3*a(n-2)+a(n-3) for n > 12.
G.f.: x*(-1-x-8*x^3-4*x^5-10*x^6+2*x^7-8*x^8-x^10-x^11)/(-1+x)^3.
MATHEMATICA
Table[n^2 + Ramp[n - 10]^2 + 4 Ramp[n - 8] Ramp[n - 7] + 4 Ramp[n - 5]^2 + 2 Ramp[n - 6] Ramp[n - 4] + 4 Ramp[n - 3] Ramp[n - 2], {n, 20}]
Join[{1, 4, 9, 24, 49, 88, 151, 236, 351}, LinearRecurrence[{3, -3, 1}, {496, 672, 880}, 11]]
CoefficientList[Series[(-1 - x - 8 x^3 - 4 x^5 - 10 x^6 + 2 x^7 - 8 x^8 - x^10 - x^11)/(-1 + x)^3, {x, 0, 20}], x]
CROSSREFS
Sequence in context: A158141 A056575 A056032 * A304908 A127979 A112262
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Mar 15 2026
STATUS
approved