A059251 A sequence related to numeric partitions and Fermat Coefficients.
1, 1, 5, 15, 44, 99, 217, 429, 811, 1430, 2438, 3978, 6312, 9690, 14550, 21318, 30669, 43263, 60115, 82225, 111044, 148005, 195143, 254475, 328759, 420732, 534076, 672452, 840656, 1043460, 1287036, 1577532, 1922745, 2330445, 2810385, 3372291
Offset: 1
Examples
a(5)= 44 because (1/8)*( 330 + 10 + 12) = 352/8; a(9)= 811 because (1/8)*(6435 + 35 + 18) = 6488/8.
Formula
Let m1^8 = A000580, m2^4 = 1 0 4 0 10 0 20 ... and let m4^2 = 1 0 0 0 2 0 0 0 3 0 0 0 4 ... Then a(n) = (1/8)*(m1^8 + m2^4 + 6*m4^2).
Empirical g.f.: x*(1 - 3*x + 5*x^2 + 3*x^3 - 4*x^4 + 3*x^5 + 5*x^6 - 3*x^7 + x^8) / ((1 - x)^8*(1 + x)^4*(1 + x^2)^2). - Colin Barker, Mar 30 2017
Extensions
More terms from David Wasserman, Jun 07 2002
Comments