OFFSET
1,1
COMMENTS
First 3 terms are all products of 2 primes.
a(4) > 10^8. - Chai Wah Wu, Aug 15 2014
a(7) > 10^13. - Giovanni Resta, Dec 09 2019
EXAMPLE
86 = 2^1*43^1, the 86th prime is 443 and 344 = 2^3*43^1.
1357 = 59^1*23^1, the 1357th prime is 11213 and 31211 = 59^1*23^2.
PROG
(Python)
from sympy import primefactors, prime
A242092 = [n for n in range(1, 10**7) if primefactors(n) == primefactors(int(str(prime(n))[::-1]))]
(PARI)
rev(n)=r=""; d=digits(n); for(i=1, #d, r=concat(Str(d[i]), r)); eval(r)
for(n=1, 10^7, p=rev(prime(n)); if(omega(n)==omega(p), if(gcd(n, p)==min(n, p), print1(n, ", ")))) \\ Derek Orr, Aug 14 2014
CROSSREFS
KEYWORD
nonn,base,more,hard
AUTHOR
Chai Wah Wu, Aug 14 2014
EXTENSIONS
a(4)-a(6) from Giovanni Resta, Dec 09 2019
STATUS
approved