The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A243527 Prime numbers containing the string 111. 3
1117, 2111, 4111, 8111, 10111, 11113, 11117, 11119, 11131, 11149, 11159, 11161, 11171, 11173, 11177, 11197, 16111, 22111, 25111, 26111, 28111, 35111, 40111, 41113, 41117, 44111, 47111, 50111, 58111, 65111, 68111, 70111, 71119, 79111, 80111 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
a(n) ~ n log n. - Charles R Greathouse IV, Jun 20 2014
MATHEMATICA
Select[Prime[Range[90000]], !StringFreeQ[ToString[#], "111"]&]
PROG
(PARI) contains(n, k)=my(N=digits(n), K=digits(k)); for(i=0, #N-#K, for(j=1, #K, if(N[i+j]!=K[j], next(2))); return(1)); 0
is(n)=isprime(n) && contains(n, 111) \\ Charles R Greathouse IV, Jun 20 2014
CROSSREFS
Cf. prime numbers containing the string kkk: this sequence (k=1), A166580 (k=2), A166581 (k=3), A166582 (k=4), A167281 (k=5), A131645 (k=6), A167282 (k=7), A167290 (k=8), A167292 (k=9).
Sequence in context: A221428 A161848 A020380 * A251360 A201034 A264312
KEYWORD
nonn,base,easy
AUTHOR
Vincenzo Librandi, Jun 06 2014
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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 27 15:55 EDT 2024. Contains 372880 sequences. (Running on oeis4.)