cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A175517 Duplicate of A163678.

Original entry on oeis.org

1913, 18379, 19013, 25013, 34613, 35879, 36979, 37379, 37813, 40013, 40213, 45613, 48091, 49279, 51613, 55313, 56179, 56713, 58613, 63079, 63179, 64091, 65479, 66413, 74779, 75913, 76213, 76579, 76679, 85313, 88379, 90379, 90679, 93113
Offset: 1

Views

Author

Zak Seidov, Jun 04 2010

Keywords

Comments

Previous name was: Smaller members of Ormiston prime pairs with the minimal gap d=18.
Possible last two digits are {13,79,91} (and in the last case necessarily last three digits are '091').
Is this a duplicate of A163678? - R. J. Mathar, Jul 22 2010

Examples

			Smallest entries of all three kinds:
a(1) = 1913 because prime(293)=1913 and prime(294)=1931 are anagrams
a(2) = 18379 because prime(2106)=18379 and prime(2107)= 18397 are anagrams
a(13) = 48091 because prime(4953)=48091 and prime(4954)= 48109 are anagrams.
		

Extensions

Marked duplicate by Joerg Arndt, Oct 13 2024

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

Original entry on oeis.org

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

Views

Author

Klaus Brockhaus and Ki Punches, Aug 05 2009

Keywords

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.

Examples

			The smallest Ormiston pair with gap 18*3 is (35617, 35671), so a(3) = 35617.
		

Crossrefs

Programs

  • 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))}

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
Showing 1-2 of 2 results.