A068659 Primes formed from the concatenation of n, n-1 and n for some n > 0.

101, 131213, 171617, 313031, 333233, 434243, 474647, 494849, 636263, 777677, 898889, 939293, 117116117, 119118119, 127126127, 133132133, 151150151, 159158159, 161160161, 163162163, 199198199, 243242243, 269268269, 273272273, 277276277

Offset: 1

Author

Amarnath Murthy, Mar 01 2002

Keywords

• base
• nonn

Links

• K. D. Bajpai, Table of n, a(n) for n = 1..10001

Programs

Maple

for n from 1 to 1000 do a := n+10^( floor(log(n)/log(10)+0.000001 )+1)*(n-1); a := a+10^( floor(log(a)/log(10)+0.000001 )+1)*n; b[n] := a:end do:k := 0:for n from 2 to 1000 doif(isprime(b[n])) then k := k+1:c[k] := b[n]:end if:end do:seq(c[j],j=1..k);

Mathematica

A068659={}; Do[t=FromDigits[Flatten[IntegerDigits/@{(n+1),n,(n+1)}]]; If[PrimeQ[t], AppendTo[A,t]], {n,500}]; A068659  (* K. D. Bajpai, Jul 03 2014 *)

Extensions

More terms from Sascha Kurz, Mar 26 2002

101 inserted by Ilya Gutkovskiy, Dec 07 2016