Main diagonal of table A083044.

Terms

a(0) =1a(1) =6a(2) =17a(3) =35a(4) =68a(5) =122a(6) =224a(7) =383a(8) =656a(9) =1092a(10) =1841a(11) =2978a(12) =4859a(13) =7835a(14) =12776a(15) =20291a(16) =32664a(17) =51422a(18) =82485a(19) =129720a(20) =204821a(21) =319482a(22) =506060a(23) =789872a(24) =1237733a(25) =1927494a(26) =3024318a(27) =4687259a(28) =7274921a(29) =11271293