Least prime divisor of E_{2*n} which does not divide any E_{2*k} with k < n, or 1 if such a primitive prime divisor of E_{2*n} does not exist, where E_m denotes the m-th Euler number given by A122045.

A242194

Least prime divisor of E_{2*n} which does not divide any E_{2*k} with k < n, or 1 if such a primitive prime divisor of E_{2*n} does not exist, where E_m denotes the m-th Euler number given by A122045.

Terms

    a(0) =1a(1) =5a(2) =61a(3) =277a(4) =19a(5) =13a(6) =47a(7) =17a(8) =79a(9) =41737a(10) =31a(11) =2137a(12) =67a(13) =29a(14) =15669721a(15) =930157a(16) =4153a(17) =37a(19) =41a(20) =137a(21) =587a(22) =285528427091a(24) =5639a(25) =53a(26) =2749a(27) =5303a(29) =6821509

External references