A163863 a(n) = smaller member p of first (i.e., smallest) Ormiston pair (p, q) with gap 18*n.

1913, 98737, 35617, 1290719, 2030789, 11117213, 26742347, 109161617, 335440351, 92801029, 46006769, 3121826537, 5322398359, 7425894361, 6640450693, 43693080679, 53568812923, 72880315369, 271695323149, 40830835151, 38116957819, 241564332377, 351336577379, 551763092297, 923411678933

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

Table of n, a(n) for n=1..25.

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

Cf. A069567, A072274, A163678, A163679, A163680, A163681, A163682.

Sequence in context: A069567 A163678 A175517 * A251917 A222928 A309031

Adjacent sequences: A163860 A163861 A163862 * A163864 A163865 A163866

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