A130651 - OEIS

%I #13 Mar 01 2015 14:51:49

%S 0,0,0,0,1,17,180,1536,11616,81552,545536,3532544,22368000,139434240,

%T 859634688,5258379264,31986270208,193796182016,1170829049856,

%U 7059331547136

%N 1/16 the number of permutations of 0..n having exactly 3 maxima.

%F Conjecture: a(n) = 2^(n-8)*(3^(n+1) - 2^(n+2)*n + 2*n^2 - 3). - _Vaclav Kotesovec_, Nov 29 2012

%F Empirical g.f.: -x^4*(3*x-1) / ((2*x-1)^3*(4*x-1)^2*(6*x-1)). - _Colin Barker_, Dec 06 2014

%F Empirical: a(n) = A000487(n+1)/16. - _R. J. Mathar_, Mar 01 2015

%Y Cf. A100575.

%K nonn

%O 0,6

%A _R. H. Hardin_, Aug 11 2007