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A050758 Primes containing at least one pair of consecutive equal digits. 5
11, 113, 199, 211, 223, 227, 229, 233, 277, 311, 331, 337, 433, 443, 449, 499, 557, 577, 599, 661, 677, 733, 773, 811, 877, 881, 883, 887, 911, 977, 991, 997, 1009, 1033, 1103, 1109, 1117, 1123, 1129, 1151, 1153, 1163, 1171, 1181, 1187, 1193, 1223, 1229 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

FORMULA

a(n) ~ n log n. - Charles R Greathouse IV, Aug 29 2015

MATHEMATICA

Select[Prime[Range[205]], MemberQ[Differences[IntegerDigits[#]], 0]&] (* Jayanta Basu, May 31 2013 *)

Select[Prime[Range[300]], SequenceCount[IntegerDigits[#], {x_, x_}]>0&] (* The program uses the SequenceCount function from Mathematica version 10 *) (* Harvey P. Dale, Feb 20 2016 *)

PROG

(PARI) is(n)=my(d=digits(n)); for(i=2, #d, if(d[i]==d[i-1], return(isprime(n)))); 0 \\ Charles R Greathouse IV, Aug 29 2015

CROSSREFS

Cf. A043096, A000040, A050757, A029743.

Sequence in context: A323477 A175684 A090227 * A166572 A111463 A142483

Adjacent sequences:  A050755 A050756 A050757 * A050759 A050760 A050761

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, Sep 15 1999

STATUS

approved

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Last modified July 25 10:07 EDT 2021. Contains 346289 sequences. (Running on oeis4.)