This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A050814 Inserting any even or any odd digit between adjacent digits of prime p produces distinct prime and composite numbers. 0
 5333, 1454969, 1466833, 1790531, 1794343, 1883113, 1984459, 2179993, 2410523, 2567891, 3100301, 3259567, 3424783, 3700153, 3954131, 3972979, 4046671, 4134133, 4280033, 4544641, 4691851, 4692641, 4848523, 5006831, 5118307 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS EXAMPLE E.g. 5333 produces five primes when an even digit is inserted (5030303, 5232323, 5434343, 5636363, 5838383) and five composites when an odd digit is inserted (5131313, 5333333, 5535353, 5737373, 5939393). MATHEMATICA a[n_, k_]:=Union[Boole/@PrimeQ[Table[FromDigits[Riffle[IntegerDigits[n], i]], {i, k+2*Range[0, 4]}]]]; t={}; Do[p=Prime[i]; x=a[p, 1]; y=a[p, 0]; If[x=={0}&&y=={1}||x=={1}&&y=={0}, AppendTo[t, p]], {i, 100, 190000}]; t (* Jayanta Basu, Jun 01 2013 *) CROSSREFS Cf. A050674-A050719. Sequence in context: A031571 A031751 A023342 * A234213 A187435 A023939 Adjacent sequences:  A050811 A050812 A050813 * A050815 A050816 A050817 KEYWORD nonn,base AUTHOR Patrick De Geest, Oct 15 1999. 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 April 25 21:06 EDT 2019. Contains 322461 sequences. (Running on oeis4.)