%I A101130
%S A101130 0,1,3,5,10,11,12,34,45,56,127,155,262,352,395,428,782,981,1057,1562,
%T A101130 1694,1815,1936,4235,4430,6857,9897
%N A101130 Indices of primes in sequence defined by A(0) = 79, A(n) = 10*A(n-1) 
               - 81 for n > 0.
%C A101130 Numbers n such that 70*10^n + 9 is prime.
%C A101130 Numbers n such that digit 7 followed by n >= 0 occurrences of digit 0 
               followed by digit 9 is prime.
%C A101130 Numbers corresponding to terms <= 981 are certified primes.
%D A101130 Klaus Brockhaus and Walter Oberschelp, Zahlenfolgen mit homogenem Ziffernkern, 
               MNU 59/8 (2006), pp. 462-467.
%H A101130 Makoto Kamada, <a href="http://homepage2.nifty.com/m_kamada/math/factorizations.htm">
               Factorizations of near-repdigit numbers</a>.
%e A101130 70009 is prime, hence 3 is a term.
%o A101130 (PARI) a=79;for(n=0,1500,if(isprime(a),print1(n,","));a=10*a-81)
%o A101130 (PARI) for(n=0,1500,if(isprime(70*10^n+9),print1(n,",")))
%Y A101130 Cf. A000533, A002275.
%Y A101130 a(n) = A097954(n) - 1.
%Y A101130 Sequence in context: A069193 A078430 A113858 this_sequence A102309 A067230 
               A075741
%Y A101130 Adjacent sequences: A101127 A101128 A101129 this_sequence A101131 A101132 
               A101133
%K A101130 nonn,hard,more
%O A101130 1,3
%A A101130 Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) and Walter Oberschelp 
               (oberschelp(AT)informatik.rwth-aachen.de), Dec 03 2004
%E A101130 More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008