A163681 - OEIS

A163681

Smaller prime p in Ormiston pairs (p, q) with q - p = 72.

1290719, 1477219, 1802419, 2520697, 2902519, 3327419, 3391697, 3498119, 4596419, 4641919, 4709519, 5521819, 5835619, 6091031, 6267419, 6642919, 6943919, 7118519, 7480519, 8241019, 8630519, 8934319, 8946919, 9859697

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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.

LINKS

Table of n, a(n) for n=1..24.

Jens Kruse Andersen, Ormiston Tuples

Eric Weisstein's World of Mathematics, Rearrangement Prime Pair

EXAMPLE

(1802419, 1802491) is an Ormiston pair with gap 72, so 1802419 is in the sequence.

MATHEMATICA

Transpose[Select[Select[Partition[Prime[Range[800000]], 2, 1], Last[#]-First[#]==72&], Sort[IntegerDigits[First[#]]]==Sort[IntegerDigits[Last[#]]]&]][[1]] (* Harvey P. Dale, Feb 14 2011 *)

PROG

(Magma) [ p: p in PrimesUpTo(10000000) | q-p eq 72 and a eq b where a is Sort(Intseq(p)) where b is Sort(Intseq(q)) where q is NextPrime(p) ];

CROSSREFS

Subsequence of A069567.

Cf. A072274, A163863.

Sequence in context: A247583 A206749 A244563 * A354560 A185776 A345083

Adjacent sequences: A163678 A163679 A163680 * A163682 A163683 A163684

KEYWORD

nonn,base

AUTHOR

Klaus Brockhaus, Aug 03 2009

EXTENSIONS

Keyword base added by Klaus Brockhaus, Sep 18 2009

STATUS

approved