A131701 Decimal expansion of the continued fraction 4+6/(9+10/(14+15/21+...)) where the terms are the semiprimes: A001358.

4, 6, 1, 9, 7, 7, 6, 8, 9, 0, 3, 3, 0, 3, 6, 8, 9, 3, 8, 0, 6, 8, 2, 1, 1, 9, 9, 6, 8, 4, 3, 7, 4, 2, 3, 8, 4, 0, 1, 7, 2, 8, 2, 5, 5, 6, 4, 4, 1, 2, 9, 2, 3, 3, 8, 9, 8, 4, 2, 0, 8, 2, 3, 2, 9, 6, 3, 7, 4, 4, 6, 3, 0, 8, 4, 4, 2, 5, 9, 6, 4, 4, 8, 6, 7, 2, 8, 7, 1, 8, 8, 0, 3, 1, 6, 6, 5, 0, 8, 2, 3, 6, 4, 2, 8

Offset: 1

Author

Jonathan Vos Post & Robert G. Wilson v, Sep 08 2007

Keywords

• cons
• nonn

Examples

			4.6197768903303689380682119968437423840172825564412923389842082329...
		

Crossrefs

Cf. A001358, A113011.

Programs

Mathematica

semiPrimeQ[n_] := Plus @@ Last /@ FactorInteger@n == 2; lst = Select[Range@ 400, semiPrimeQ@ # &]; First@ RealDigits@ N[ Fold[ Last@ #2 + First@ #2/#1 &, 4, Partition[Reverse@ lst, 2]], 111] (* Robert G. Wilson v *)