A100473 -id:A100473 - cp's OEIS frontend

A100999 Indices of primes in sequence defined by A(0) = 97, A(n) = 10*A(n-1) - 53 for n > 0.

0, 16, 22, 72, 130, 472, 684, 700, 1908, 3028, 3472, 4192, 9930

Offset: 1

Klaus Brockhaus and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Nov 27 2004

Numbers n such that (820*10^n + 53)/9 is prime.
Numbers n such that digit 9 followed by n >= 0 occurrences of digit 1 followed by digit 7 is prime.
Numbers corresponding to terms <= 700 are certified primes.
a(14) > 10^5. - Robert Price, Oct 25 2015

			911111111111111117 is prime, hence 16 is a term.

Klaus Brockhaus and Walter Oberschelp, Zahlenfolgen mit homogenem Ziffernkern, MNU 59/8 (2006), pp. 462-467.

Makoto Kamada, Prime numbers of the form 911...117.
Index entries for primes involving repunits.

Cf. A000533, A002275, A100473.

Select[Range[0, 100000], PrimeQ[(820*10^# + 53)/9] &] (* Robert Price, Oct 25 2015 *)

a=97;for(n=0,1000,if(isprime(a),print1(n,","));a=10*a-53)

for(n=0,1000,if(isprime((820*10^n+53)/9),print1(n,",")))

a(n) = A100473(n) - 1.

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008

A101393 Numbers k such that 3*10^k + R_k + 6 is prime, where R_k = 11...1 is the repunit (A002275) of length k.

Original entry on oeis.org

1, 2, 218, 692, 1805, 2207, 2873, 59135

Offset: 1

Julien Peter Benney (jpbenney(AT)ftml.net), Jan 15 2005

nonn

Also numbers k such that (28*10^k + 53)/9 is prime.

All except 1, 2 and 218 only probably prime. No others less than 10000.

			n = 1, 2 are members since 37 and 317 are primes.

Makoto Kamada, Prime numbers of the form 311...117.
Index entries for primes involving repunits.

Cf. A100501, A100473, A101826.

Do[ If[ PrimeQ[(28*10^n+53)/9], Print[n]], {n, 0, 10000}]

a(n) = A101826(n) + 1.

a(8) from Kamada data by Robert Price, Dec 13 2010

cp's OEIS Frontend

A100999 Indices of primes in sequence defined by A(0) = 97, A(n) = 10*A(n-1) - 53 for n > 0.

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