Number of irreducible positions of size n in Montreal solitaire.

Terms

a(0) =1a(1) =4a(2) =14a(3) =42a(4) =123a(5) =351a(6) =988a(7) =2761a(8) =7682a(9) =21313a(10) =59029a(11) =163314a(12) =451529a(13) =1247842a(14) =3447574a(15) =9523375a(16) =26303825a(17) =72646588a(18) =200627795a(19) =554056162a(20) =1530058222a(21) =4225290890a(22) =11668141901a(23) =32221405479a(24) =88978639438a(25) =245711832196a(26) =678524838258