Rectified hexateron (5-simplex) numbers: the coefficient of x^(2n-2) in (1+x+x^2+...+x^(n-1))^6.

Terms

a(0) =0a(1) =1a(2) =15a(3) =90a(4) =336a(5) =951a(6) =2247a(7) =4676a(8) =8856a(9) =15597a(10) =25927a(11) =41118a(12) =62712a(13) =92547a(14) =132783a(15) =185928a(16) =254864a(17) =342873a(18) =453663a(19) =591394a(20) =760704a(21) =966735a(22) =1215159a(23) =1512204a(24) =1864680a(25) =2280005a(26) =2766231a(27) =3332070a(28) =3986920a(29) =4740891