This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A183176 Numbers n such that (10^(2n+1)+12*10^n-1)/3 is prime. 1
 1, 3, 7, 11, 13, 17, 29, 31, 33, 77, 933, 1555, 11758 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(14) > 100,000. - Robert Price, Dec 29 2016 REFERENCES C. Caldwell and H. Dubner, "Journal of Recreational Mathematics", Volume 28, No. 1, 1996-97, pp. 1-9. LINKS Patrick De Geest, World!Of Numbers, Palindromic Wing Primes (PWP's) Makoto Kamada, Prime numbers of the form 33...33733...33 FORMULA a(n) = (A077790(n)-1)/2. MATHEMATICA Do[If[PrimeQ[(10^(2n + 1) + 12*10^n - 1)/3], Print[n]], {n, 3000}] PROG (PARI) is(n)=ispseudoprime((10^(2*n+1)+12*10^n-1)/3) \\ Charles R Greathouse IV, Jun 13 2017 CROSSREFS Cf. A004023, A077775-A077798, A107123-A107127, A107648, A107649, A115073, A183174-A183187. Sequence in context: A020618 A184865 A055211 * A045417 A260379 A045418 Adjacent sequences:  A183173 A183174 A183175 * A183177 A183178 A183179 KEYWORD nonn,more,base AUTHOR Ray Chandler, Dec 28 2010 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.