cp's OEIS Frontend

A224846 Smallest k such that (10^n+k, 10^n+k+2) and (10^(n+1)+k, 10^(n+1)+k+2) are two pairs of twin primes with k(n+1) > k(n).

%I A224846 #16 Jul 24 2013 12:48:39
%S A224846 1,49,91,1117,2929,3001,4831,37237,43897,54409,55669,81931,89809,
%T A224846 194971,271159,556651,628069,639247,1036447,1615597,2075407,2086447,
%U A224846 2414077,3331009,3442789,4088539,4178311,4330681,5834869,6846649,7928047,11222341,15520927,18575911,18615787,22426969,22645189
%N A224846 Smallest k such that (10^n+k, 10^n+k+2) and (10^(n+1)+k, 10^(n+1)+k+2) are two pairs of twin primes with k(n+1) > k(n).
%H A224846 Pierre CAMI, <a href="/A224846/b224846.txt">Table of n, a(n) for n = 1..75</a>
%e A224846 10^1+1=11 prime as 13 10^2+1=101 prime as 103 so a(1)=1.
%t A224846 i = -1; Table[i = i + 2; While[! (PrimeQ[10^n + i] && PrimeQ[10^n + i + 2] && PrimeQ[10^(n + 1) + i] && PrimeQ[10^(n + 1) + i + 2]), i = i + 2]; i, {n, 10}] (* _T. D. Noe_, Jul 23 2013 *)
%o A224846 PFGW & SCRIPTIFY
%o A224846 SCRIPT
%o A224846 DIM n,0
%o A224846 DIM k,-1
%o A224846 DIMS t
%o A224846 OPENFILEOUT myf,a(n).txt
%o A224846 LABEL a
%o A224846 SET n,n+1
%o A224846 LABEL b
%o A224846 SET k,k+2
%o A224846 SETS t,%d,%d\,;n;k
%o A224846 PRP 10^n+k,t
%o A224846 IF ISPRP THEN GOTO c
%o A224846 GOTO b
%o A224846 LABEL c
%o A224846 PRP 10^n+k+2,t
%o A224846 IF ISPRP THEN GOTO d
%o A224846 GOTO b
%o A224846 LABEL d
%o A224846 PRP 10^(n+1)+k,t
%o A224846 IF ISPRP THEN GOTO e
%o A224846 GOTO b
%o A224846 LABEL e
%o A224846 PRP 10^(n+1)+k+2,t
%o A224846 IF ISPRP THEN GOTO f
%o A224846 GOTO b
%o A224846 LABEL f
%o A224846 WRITE myf,t
%o A224846 SET k,k+2
%o A224846 GOTO a
%Y A224846 Cf. A124001 (10^n+k and 10^n+k+2 are prime).
%K A224846 nonn
%O A224846 1,2
%A A224846 _Pierre CAMI_, Jul 22 2013