The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A102527 Numbers k such that k111111 is prime. 2
 29, 34, 61, 71, 80, 85, 89, 94, 101, 103, 106, 107, 115, 118, 122, 124, 128, 131, 149, 158, 163, 166, 193, 194, 199, 205, 212, 233, 248, 251, 256, 265, 268, 277, 290, 316, 323, 326, 328, 346, 347, 355, 356, 361, 365, 367, 382, 383, 386, 389, 394, 398, 404, 424, 430, 431, 436, 439, 452, 454, 457 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Daniel Starodubtsev, Table of n, a(n) for n = 1..10000 EXAMPLE If k=29, then k111111 = 29111111 (prime). If k=101, then k111111 = 101111111 (prime). If k=122, then k111111 = 122111111 (prime). MATHEMATICA ect[Range[500], PrimeQ[FromDigits[Join[IntegerDigits[#], {1, 1, 1, 1, 1, 1} ]]]&] (* Harvey P. Dale, Aug 22 2011 *) PROG (MAGMA) [ n: n in [1..700] | IsPrime(Seqint([1, 1, 1, 1, 1, 1] cat Intseq(n))) ]; // Vincenzo Librandi, Feb 04 2011 CROSSREFS Sequence in context: A031172 A159022 A280643 * A039307 A043130 A043910 Adjacent sequences:  A102524 A102525 A102526 * A102528 A102529 A102530 KEYWORD base,nonn AUTHOR Parthasarathy Nambi, Feb 24 2005 STATUS approved

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

Last modified December 3 11:58 EST 2021. Contains 349462 sequences. (Running on oeis4.)