A101826 Indices of primes in sequence defined by A(0) = 37, A(n) = 10*A(n-1) - 53 for n > 0.
0, 1, 217, 691, 1804, 2206, 2872, 59134
Offset: 1
Examples
317 is prime, hence 1 is a term.
References
- Klaus Brockhaus and Walter Oberschelp, Zahlenfolgen mit homogenem Ziffernkern, MNU 59/8 (2006), pp. 462-467.
Links
Programs
-
Mathematica
nn=2900;Transpose[Select[Thread[{NestList[10#-53&,37,nn], Range[0,nn]}], PrimeQ[First[#]]&]] [[2]] (* Harvey P. Dale, Mar 26 2011 *) -
PARI
a=37;for(n=0,2000,if(isprime(a),print1(n,","));a=10*a-53)
-
PARI
for(n=0,2000,if(isprime((280*10^n+53)/9),print1(n,",")))
Formula
a(n) = A101393(n) - 1.
Extensions
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008
a(8) derived from A101393 by Robert Price, Jan 26 2015
Comments