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A229903 (190/99)*(100^A001651(n)-1). 1
190, 19190, 191919190, 19191919190, 191919191919190, 19191919191919190, 191919191919191919190, 19191919191919191919190, 191919191919191919191919190, 19191919191919191919191919190, 191919191919191919191919191919190 (list; graph; refs; listen; history; text; internal format)
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

Table of n, a(n) for n=1..11.

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

Cf. A000010, A001651, A004086, A097647.

Sequence in context: A184192 A263523 A133241 * A221386 A217225 A207211

Adjacent sequences:  A229900 A229901 A229902 * A229904 A229905 A229906

KEYWORD

nonn,easy

AUTHOR

Jahangeer Kholdi, Oct 17 2013

STATUS

approved

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Last modified September 24 11:03 EDT 2020. Contains 337317 sequences. (Running on oeis4.)