A093152 Number of odd composites below 10^n that are congruent to 3 modulo 4.

0, 12, 163, 1881, 20192, 210678, 2167602, 22119050, 224575958, 2272470765, 22940965468, 231196012323, 2326967172345, 23397529032871, 235077714312816, 2360380827753871, 23688221418030854, 237630022854838725, 2382971166321456083, 23889590198589663868

Offset: 1

Author

Enoch Haga, Mar 24 2004

Keywords

• nonn

Examples

			Below 10^2 there are 12 odd composites 3 mod 4 so a(2)=12
		

Crossrefs

Cf. A093151 A093153 A091295 A091098 A091099.

Formula

For n>1, a(n) = 25*10^(n-2) - A091099(n) [From Max Alekseyev, May 17 2009]

Extensions

a(9) from Ryan Propper, Jun 21 2005

a(10)-a(20) from Max Alekseyev, May 17 2009, Oct 08 2013