A027540 Second diagonal of A027537.
3, 16, 55, 156, 399, 960, 2223, 5020, 11143, 24432, 53079, 114492, 245535, 524032, 1113823, 2358972, 4980375, 10485360, 22019655, 46136860, 96468463, 201326016, 419429775, 872414556, 1811938599, 3758095600, 7784627383, 16106126460, 33285995583, 68719475712
Offset: 2
Links
- Vincenzo Librandi, Table of n, a(n) for n = 2..1000
Crossrefs
Cf. A027537.
Programs
-
Magma
[(n+1)*(2^n-n-1): n in [2..30]]; // Vincenzo Librandi, Sep 04 2017
-
Mathematica
Table[(n + 1) (2^n - n - 1), {n, 2, 35}] (* Vincenzo Librandi, Sep 04 2017 *)
Formula
Numerators of sequence a[ n, n-1 ] in (a[ i, j ])^2 where a[ i, j ] = A(i, j)/i! if j <= i, 0 if j > i.
a(n) = (n+1)*(2^n - n - 1). - Vladeta Jovovic, Aug 18 2002
G.f.: x^2*(-3+5*x)/((2*x-1)^2*(x-1)^3). - Maksym Voznyy (voznyy(AT)mail.ru), Aug 14 2009; corrected by R. J. Mathar, Sep 16 2009
a(n) = Sum_{k=0..n} Sum_{i=0..n} (i-k) * C(n-k,i-2). - Wesley Ivan Hurt, Sep 19 2017
Extensions
More terms from Vladeta Jovovic, Aug 18 2002