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 A360605 The polygonal polynomials evaluated at x = -1/2 and normalized with (-2)^n. 1
 0, 1, 0, 1, 0, -3, 8, -31, 72, -195, 448, -1071, 2416, -5475, 12120, -26719, 58232, -126243, 271824, -582575, 1242720, -2640899, 5592360, -11806239, 24855080, -52195843, 109362528, -228667311, 477218512, -994205475, 2067947128, -4294967391, 8908080216 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,6 COMMENTS The coefficients of the polygonal polynomials are the antidiagonals of A139600. LINKS Table of n, a(n) for n=0..32. FORMULA a(n) = (-2)^n * Sum_{k=0..n} A139600(n, k) * (-2)^(-k). a(n) = [x^n] x*(4*x^2 - x - 1) / ((2*x + 1)^2*(x - 1)^3). a(n) = (4 - n)*(3*n + 2 + (-2)^(n + 1)) / 27. MAPLE a := n -> (1/27)*(4-n)*(3*n + 2 + (-2)^(n + 1)): seq(a(n), n = 0..32); CROSSREFS Cf. A139600, A360606. Sequence in context: A145776 A066165 A323775 * A119838 A148889 A148890 Adjacent sequences: A360602 A360603 A360604 * A360606 A360607 A360608 KEYWORD sign AUTHOR Peter Luschny, Feb 21 2023 STATUS approved

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Last modified February 25 19:44 EST 2024. Contains 370332 sequences. (Running on oeis4.)