A068707 Smallest prime obtained as a right concatenation of n consecutive even numbers and 1.

41, 241, 1101121141, 101214161, 2468101, 246810121, 6810121416181, 50525456586062641, 1618202224262830321, 8284868890929496981001, 52545658606264666870721, 4244464850525456586062641

Offset

1,1

Links

Table of n, a(n) for n=1..12.

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

Adjacent sequences: A068704 A068705 A068706 * A068708 A068709 A068710

Keyword

base,nonn

Author

Amarnath Murthy, Mar 04 2002

Extensions

More terms from Sascha Kurz, Mar 27 2002

Status

approved