The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A269564 Seven-digit primes whose first, third, fifth, and seventh digits are the same. 2
 1010131, 1011191, 1012171, 1014121, 1014131, 1014161, 1015171, 1016111, 1017131, 1110181, 1111151, 1111181, 1112131, 1112141, 1112171, 1113181, 1114111, 1115131, 1117111, 1118101, 1119121, 1210151, 1211141, 1211191, 1212121, 1212191, 1213141, 1213151 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS There are 598 such primes. LINKS Harvey P. Dale, Table of n, a(n) for n = 1..598 EXAMPLE 7671737 is a prime and its first, third, fifth, and seventh digits are the same. MATHEMATICA Table[Select[Prime[Range[PrimePi[i*10^6]+1, PrimePi[i*10^6+ 10^6-1]]], MatchQ[ IntegerDigits[#], {x_, _, x_, _, x_, _, x_}]&], {i, {1, 3, 7, 9}}] //Flatten CROSSREFS Cf. A269066. Sequence in context: A306515 A306517 A043643 * A096931 A210274 A252916 Adjacent sequences:  A269561 A269562 A269563 * A269565 A269566 A269567 KEYWORD nonn,base,fini,full AUTHOR Harvey P. Dale, Feb 29 2016 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 28 15:04 EDT 2022. Contains 354115 sequences. (Running on oeis4.)