A028380 - OEIS

%I #6 Dec 15 2015 10:06:59

%S 0,28,148,621,2420,9152,34164,126854,470288,1744200,6478088,24107105,

%T 89908380

%N a_n = - sum_{i=1..n-1} C(i+1, n-i) (-1)^(n-i) a_i.

%C The values do not reflect the definition. They seem to be defined by (n-1)*(9*n+10)*(n+5) * a(n) = 2*n*(9*n+19)*(2*n+3) *a(n-1), n>1. - _R. J. Mathar_, Dec 15 2015

%K nonn,obsc

%O 0,2

%A Grisha Berkolaiko (grisha(AT)ORY.ph.biu.ac.il)