OFFSET
1,1
COMMENTS
For each term p except 2, A013632(p) is divisible by 6.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
a(3) = 83 is a term because it is prime, the next prime is 89, and 83+98 = 181 and 38+89 = 127 are both prime.
MAPLE
revdigs:= proc(n) local L, i; L:= convert(n, base, 10);
add(L[-i]*10^(i-1), i=1..nops(L))
end proc:
Primes:= select(isprime, [2, seq(i, i=3..10000, 2)]):
RPrimes:= map(revdigs, Primes):
Primes[select(i -> isprime(Primes[i]+RPrimes[i+1]) and isprime(RPrimes[i]+Primes[i+1]), [$1..nops(Primes)-1])]:
CROSSREFS
KEYWORD
nonn,base
AUTHOR
J. M. Bergot and Robert Israel, Mar 20 2022
STATUS
approved