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!)
A068707 Smallest prime obtained as a right concatenation of n consecutive even numbers and 1. 0
41, 241, 1101121141, 101214161, 2468101, 246810121, 6810121416181, 50525456586062641, 1618202224262830321, 8284868890929496981001, 52545658606264666870721, 4244464850525456586062641 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
a(3) = 1101121141 as it is the smallest prime which is a concatenation of three consecutive even numbers 110,112,114 and a 1.
MAPLE
for i from 1 to 30 do k := 0:c := true:while(c) do a := 2*(1+k):for j from i-2 to 0 by -1 do a := 2*(i-j+k)+10^(floor(log(2*(i-j+k))/log(10)+0.000001)+1)*a; end do:a := 10*a+1:k := k+1: if(isprime(a)) then := false:end if:end do:b[i] := a:end do:seq(b[k], k=1..30);
MATHEMATICA
Table[k=0; While[!PrimeQ[x=FromDigits[Join[Flatten[Table[IntegerDigits[k+2n], {n, m}]], {1}]]], k=k+2]; x, {m, 12}] (* Jayanta Basu, May 22 2013 *)
CROSSREFS
Cf. A068706.
Sequence in context: A167443 A098675 A056213 * A069761 A322241 A140634
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Mar 04 2002
EXTENSIONS
More terms from Sascha Kurz, Mar 27 2002
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 March 29 09:32 EDT 2024. Contains 371268 sequences. (Running on oeis4.)