a(n) = floor(E_(n+1)/E_(n)) where E_n is n-th Euler number (see A028296 and A000364).

Terms

a(0) =5a(1) =12a(2) =22a(3) =36a(4) =53a(5) =73a(6) =97a(7) =124a(8) =154a(9) =187a(10) =223a(11) =263a(12) =306a(13) =352a(14) =402a(15) =454a(16) =510a(17) =569a(18) =632a(19) =697a(20) =766a(21) =838a(22) =914a(23) =992a(24) =1074a(25) =1159a(26) =1248a(27) =1339a(28) =1434a(29) =1532