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A308600
Number of (not necessarily maximal) cliques in the n X n antelope graph.
1
2, 5, 10, 17, 34, 61, 98, 145, 202, 269, 346, 433, 530, 637, 754, 881, 1018, 1165, 1322, 1489, 1666, 1853, 2050, 2257, 2474, 2701, 2938, 3185, 3442, 3709, 3986, 4273, 4570, 4877, 5194, 5521, 5858, 6205, 6562, 6929, 7306, 7693, 8090, 8497, 8914, 9341, 9778, 10225, 10682, 11149
OFFSET
1,1
LINKS
Eric Weisstein's World of Mathematics, Antelope Graph
Eric Weisstein's World of Mathematics, Clique
FORMULA
a(n) = 5*n^2-28*n+49 for n >= 3.
From Colin Barker, Jun 10 2019: (Start)
G.f.: x*(2 - x + x^2 + 8*x^4) / (1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>5.
(End)
MATHEMATICA
Table[Piecewise[{{2, n == 1}, {5, n == 2}}, 49 - 28 n + 5 n^2], {n, 20}]
PROG
(PARI) Vec(x*(2 - x + x^2 + 8*x^4) / (1 - x)^3 + O(x^50)) \\ Colin Barker, Jun 10 2019
CROSSREFS
Sequence in context: A372683 A342172 A262406 * A308604 A018315 A146220
KEYWORD
nonn,easy
AUTHOR
Eric W. Weisstein, Jun 09 2019
STATUS
approved