Kochański's (or Kochanski's) sequence.

Terms

a(0) =15a(1) =4697a(2) =5548a(3) =14774a(4) =33696a(5) =61072a(6) =111231a(7) =115985a(8) =173819a(9) =563316a(10) =606004a(11) =1751458a(12) =1952544a(13) =3046715a(14) =4397195a(15) =45051907a(16) =653475595a(17) =734915444a(18) =1241384578a(19) =2438767174a(20) =2557084119a(21) =5090226634a(22) =6088149715a(23) =18483120028a(24) =44254634530a(25) =48502484589a(26) =70835215004