Number of compositions of 5*n-2 into parts 1 and 5.

Terms

a(0) =1a(1) =5a(2) =20a(3) =80a(4) =325a(5) =1326a(6) =5411a(7) =22076a(8) =90061a(9) =367411a(10) =1498887a(11) =6114853a(12) =24946129a(13) =101770120a(14) =415180936a(15) =1693770328a(16) =6909898016a(17) =28189589705a(18) =115002126790a(19) =469162173146