A244211 - OEIS

%I #41 Jun 13 2017 03:50:43

%S 133946,213410,299144,33845,367256,803676,1214450,1250446,1280460,

%T 1704478,1780150,1792762,1794864,2003070,2004962,2203536,2798489,

%U 3014465,3027709,3041998,3053350,3194549,3326301,4244794

%N Integers n such that for every integer k>0, n*6^k-1 has a divisor in the set { 7, 13, 31, 37, 43 }.

%C For n > 24 a(n) = a(n-24) + 4488211, the first 24 values are in the data.

%C When the number a(n) has 1 or 6 as the last digit, the number a(n)*6^k-1 is always divisible by 5 and always has another divisor in the set { 7, 13, 31, 37, 97 } for every k.

%F For n > 24, a(n) = a(n-24) + 4488211.

%o (PFGW & SCRIPT)

%o SCRIPT

%o DIM k,1

%o DIM n

%o DIMS t

%o OPENFILEOUT myf,res.txt

%o LABEL loop1

%o SET k,k+1

%o SET n,0

%o LABEL loop2

%o SET n,n+1

%o IF n>500 THEN GOTO a

%o IF (k*6^n-1)%7==0 THEN GOTO loop2

%o IF (k*6^n-1)%13==0 THEN GOTO loop2

%o IF (k*6^n-1)%31==0 THEN GOTO loop2

%o IF (k*6^n-1)%37==0 THEN GOTO loop2

%o IF (k*6^n-1)%43==0 THEN GOTO loop2

%o GOTO loop1

%o LABEL a

%o WRITE myf,k

%o PRINT k

%o GOTO loop1

%Y Cf. A076337, A243969, A244070, A244071, A244072, A244073, A244074, A244076.

%K nonn

%O 1,1

%A _Pierre CAMI_, Jun 23 2014