5,1

a(n)= A053131(n)/2

a(n)= binomial(2*n-8, 9)/2 if n >= 9 else 0; G.f.: (5+60*x+126*x^2+60*x^3+5*x^4)/(1-x)^10.

Cf. A053131.

Sequence in context: A012122 A012091 A003465 this_sequence A002400 A086805 A163014

Adjacent sequences: A053130 A053131 A053132 this_sequence A053134 A053135 A053136

nonn,easy

Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de)