A161559 Engel expansion of tan(1/2).

2, 11, 54, 136, 1473, 3483, 36244, 41086, 305728, 379955, 582669, 4540387, 5020443, 22096761, 24228660, 48364856, 178868536, 234516235, 524137295, 1096104266, 11627672572, 19828856452, 31372689367, 47247829739, 701124643395

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Jun 13 2009

Keywords

• nonn

Examples

			A161011 = 0.546302.... = 1/2+1/(2*11)+1/(2*11*54)+1/(2*11*54*136)+ ...
		

Links

• Index to sequences related to Engel expansions

Crossrefs

Cf. A006784.

Programs

Mathematica

EngelExp[A_,n_]:=Join[Array[1&,Floor[A]],First@Transpose@NestList[{Ceiling[1/ Expand[ #[[1]]#[[2]]-1]],Expand[ #[[1]]#[[2]]-1]}&,{Ceiling[1/(A-Floor[A])], A-Floor[A]},n-1]]; EngelExp[N[Tan[1/2],6! ],50]

Extensions

Example added by R. J. Mathar, Oct 04 2009