A078225 a(n) = A078221(n+1)/A078221(n).

3, 3, 11, 101, 10001, 100000001, 10000000000000001, 100000000000000000000000000000001, 10000000000000000000000000000000000000000000000000000000000000001

Offset: 1

Author

Amarnath Murthy, Nov 23 2002

Keywords

• base
• nonn

Crossrefs

Cf. A078221, A078222, A078223, A078224.

Programs

Maple

A078221 := proc(n) if n =1 then 1 ; elif n = 2 then 3 ; else 10^(2^(n-3))-1 ; fi ; end: A078225 := proc(n) A078221(n+1)/A078221(n) ; end: for n from 1 to 20 do print(A078225(n)) ; od ; # R. J. Mathar, Feb 03 2007, using the formula for A078221

Formula

For n>2, a(n) = 10^(2^(n-3))+1

Extensions

More terms from R. J. Mathar, Feb 03 2007, using the formula for A078221

a(5) corrected by Max Alekseyev, Aug 21 2013