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Odd integers n such that for every integer k>0, n*2^k-1 has a divisor in the set { 3, 5, 7, 13, 17, 97, 673 }.
1

%I #10 Apr 25 2016 11:50:03

%S 73520771,108288041,127499219,141239113,160792529,198545797,205293103,

%T 217763051,227258803,262056089,269931509,303224819,307060289,

%U 353982553,368427809,430034677,525141899,581603107,585721991,600824113,612314921,644606467,718519237,723522461

%N Odd integers n such that for every integer k>0, n*2^k-1 has a divisor in the set { 3, 5, 7, 13, 17, 97, 673 }.

%C For n > 96 a(n) = a(n-96) + 3029691210, the first 96 values are given in the table.

%H Pierre CAMI, <a href="/A244924/b244924.txt">Table of n, a(n) for n = 1..96</a>

%F For n > 96 a(n)=a(n-96) + 3029691210

%o (PFGW & SCRIPT)

%o SCRIPT

%o DIM k

%o DIM n,73520701

%o OPENFILEOUT myf,a(n).txt

%o LABEL loop1

%o SET n,n+2

%o IF n>3103211981 THEN END

%o SET k,0

%o LABEL loop2

%o SET k,k+1

%o IF k>300 THEN GOTO a

%o IF (n*2^k-1)%3==0 THEN GOTO loop2

%o IF (n*2^k-1)%5==0 THEN GOTO loop2

%o IF (n*2^k-1)%7==0 THEN GOTO loop2

%o IF (n*2^k-1)%13==0 THEN GOTO loop2

%o IF (n*2^k-1)%17==0 THEN GOTO loop2

%o IF (n*2^k-1)%97==0 THEN GOTO loop2

%o IF (n*2^k-1)%673==0 THEN GOTO loop2

%o GOTO loop1

%o LABEL a

%o WRITE myf,n

%o GOTO loop1

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

%K nonn

%O 1,1

%A _Pierre CAMI_, Jul 08 2014