Lee's empirically improved Tokuda gaps for shellsort.

Terms

a(0) =1a(1) =4a(2) =9a(3) =20a(4) =45a(5) =102a(6) =230a(7) =516a(8) =1158a(9) =2599a(10) =5831a(11) =13082a(12) =29351a(13) =65853a(14) =147748a(15) =331490a(16) =743735a(17) =1668650a(18) =3743800a(19) =8399623a(20) =18845471a(21) =42281871a(22) =94863989a(23) =212837706a(24) =477524607a(25) =1071378536a(26) =2403754591a(27) =5393085583a(28) =12099975682a(29) =27147615084