Number of winning paths of length n+1 across an n X n Hex board.

Terms

a(0) =2a(1) =14a(2) =58a(3) =194a(4) =578a(5) =1602a(6) =4226a(7) =10754a(8) =26626a(9) =64514a(10) =153602a(11) =360450a(12) =835586a(13) =1916930a(14) =4358146a(15) =9830402a(16) =22020098a(17) =49020930a(18) =108527618a(19) =239075330a(20) =524288002a(21) =1145044994a(22) =2491416578a(23) =5402263554a(24) =11676942338a(25) =25165824002a(26) =54089744386a(27) =115964116994a(28) =248034361346