a(n) = Sum_{i=1..n} C(i+4,5)^2.

Terms

a(0) =1a(1) =37a(2) =478a(3) =3614a(4) =19490a(5) =82994a(6) =296438a(7) =923702a(8) =2580071a(9) =6588075a(10) =15606084a(11) =34685508a(12) =72976852a(13) =146387476a(14) =281597860a(15) =521971876a(16) =936053677a(17) =1629533233a(18) =2761788434a(19) =4568378450a(20) =7391175350a(21) =11718183750a(22) =18235516650a(23) =27894475050a(24) =41997225075a(25) =62305185111