OFFSET
1,1
COMMENTS
This sequence is a subsequence of A097647. Because if 3 does not divide m then gcd(100^m-1,19*91)=1 and we have phi(190*(100^m-1)/99)=phi(190)*phi((100^m-1)/9)=phi(91)*phi((100^m-1)/99)=phi(91*(100^m-1)/99)=phi(reversal(190*(100^m-1)/99)).
LINKS
Index entries for linear recurrences with constant coefficients, signature (1,1000000,-1000000).
FORMULA
a(n) = (100/99)*(100^floor((3n-1)/2)-1).
G.f.: 190*x*(10000*x^2+100*x+1) / ((x-1)*(1000*x-1)*(1000*x+1)). - Colin Barker, Nov 01 2013
MATHEMATICA
Table[190/99*(100^Floor[(3n-1)/2]-1), {n, 11}]
PROG
(PARI) Vec(190*x*(10000*x^2+100*x+1)/((x-1)*(1000*x-1)*(1000*x+1)) + O(x^100)) \\ Colin Barker, Nov 01 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jahangeer Kholdi, Oct 17 2013
STATUS
approved