OFFSET
1,1
COMMENTS
Sum of reciprocals converges towards 0.421066...
It is only a (plausible) conjecture that this sequence is well-defined. See A152052. - N. J. A. Sloane, Aug 22 2014
LINKS
Abhiram R Devesh, Table of n, a(n) for n = 1..100
FORMULA
For n > 1, a(n) = 10^(n-1) + A227432(n-1), assuming a(n) exists. - Jens Kruse Andersen, Aug 22 2014
PROG
(Python)
import sympy
for i in range(100):
a=(10**i)
p=sympy.nextprime(a)
while not sympy.isprime(p+4):
p=sympy.nextprime(p)
print(p)
(PARI)
a(n)=my(p=nextprime(10^(n-1))); while(!isprime(p+4), p=nextprime(p+1)); return(p)
vector(50, n, a(n)) \\ Derek Orr, Aug 04 2014
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Abhiram R Devesh, Aug 02 2014
STATUS
approved