a(n) = gcd( binomial(n+3, n) + binomial(n+4, n+1), binomial(n+5, n+2) ).

Terms

a(0) =2a(1) =5a(2) =1a(3) =7a(4) =20a(5) =3a(6) =5a(7) =11a(8) =2a(9) =65a(10) =7a(11) =5a(12) =8a(13) =17a(14) =15a(15) =19a(16) =10a(17) =7a(18) =11a(19) =115a(20) =4a(21) =25a(22) =13a(23) =9a(24) =70a(25) =29a(26) =5a(27) =31a(28) =16a(29) =55