A101397 -id:A101397 - cp's OEIS frontend

A101713 Indices of primes in sequence defined by A(0) = 43, A(n) = 10*A(n-1) - 27 for n > 0.

0, 2, 6, 9, 39, 418, 448, 1736, 2244, 3130, 3812, 5344, 5658, 5680, 8409, 9096, 11292, 21060

Offset: 1

Klaus Brockhaus and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Dec 14 2004

Numbers n such that 40*10^n + 3 is prime.
Numbers n such that digit 4 followed by n >= 0 occurrences of digit 0 followed by digit 3 is prime.
Numbers corresponding to terms <= 448 are certified primes.
a(19) > 2*10^5. - Robert Price, Jul 17 2015

			4003 is prime, hence 2 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 400...003.

Cf. A000533, A002275, A101397.

Select[Range[0,300],PrimeQ[40*10^#+3]&] (* Robert Price, Jul 17 2015 *)

a=43;for(n=0,1500,if(isprime(a),print1(n,","));a=10*a-27)

for(n=0,1500,if(isprime(40*10^n+3),print1(n,",")))

a(n) = A101397(n+1) - 1.

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008

a(17)-a(18) from Kamada data by Ray Chandler, Apr 30 2015

A177507 Primes of the form 4*10^n+3.

Original entry on oeis.org

7, 43, 4003, 40000003, 40000000003, 40000000000000000000000000000000000000003

Offset: 1

Vincenzo Librandi, Dec 11 2010

nonn

a(9) has 1738 digits. - Vincenzo Librandi, Jan 03 2014

Vincenzo Librandi, Table of n, a(n) for n = 1..8
Makoto Kamada, Prime numbers of the form 400...003.

Cf. A101397.

[a: n in [0..250] | IsPrime(a) where a is 4*10^n+3];

Select[Table[4 10^n + 3, {n, 0, 300}], PrimeQ] (* Vincenzo Librandi, Jan 03 2014 *)

cp's OEIS Frontend

A101713 Indices of primes in sequence defined by A(0) = 43, A(n) = 10*A(n-1) - 27 for n > 0.

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