OFFSET
1,1
COMMENTS
An Ormiston pair (or rearrangement prime pair) is a pair of consecutive primes that use the same digits in a different order. The gap q - p of an Ormiston pair (p, q) is a multiple of 18.
LINKS
Jens Kruse Andersen, Ormiston Tuples
Eric Weisstein's World of Mathematics, Rearrangement Prime Pair
EXAMPLE
The smallest Ormiston pair with gap 18*3 is (35617, 35671), so a(3) = 35617.
PROG
(PARI) {m=20; v=vector(m); p=1; while(p<10^10, q=nextprime(p+1); gap=q-p; if(gap%18==0&&v[j=gap\18]==0&&vecsort(Vec(Str(p)))==vecsort(Vec(Str(q))), v[j]=p; print(p, ", ", q, ", ", gap, ", ")); p=q); print(); for(j=1, m, if(v[j]>0, print1(v[j], ", "), break))}
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Klaus Brockhaus and Ki Punches, Aug 05 2009
EXTENSIONS
Definition clarified by Klaus Brockhaus and Ki Punches, Aug 08 2009
a(17)-a(19) and a(22) from Klaus Brockhaus and Ki Punches, Aug 13 2009
a(23)-a(25) from Klaus Brockhaus, Sep 07 2009
STATUS
approved