%I #11 Nov 15 2013 05:27:10

%S 6,26781,120791,5099531,5720435,14637451,24110358,31552261,33792198,

%T 57804181,71925054,88324781,92849126,441031331,650715071,924029951,

%U 1425902869,2093676486,2336689491,3273172441,4533042611,4711366831,5162021871,5502040431,6427899582

%N Composite squarefree numbers n such that p(i)+6 divides n-6, where p(i) are the prime factors of n.

%e Prime factors of 14637451 are 41, 229 and 1559. We have that (14637451-6)/(41+6) = 311435, (14637451-6)/(229+6) = 62287 and (14637451-6)/(1559+6) = 9353.

%p with(numtheory); A225716:=proc(i,j) local c, d, n, ok, p, t;

%p for n from 2 to i do if not isprime(n) then p:=ifactors(n)[2]; ok:=1;

%p for d from 1 to nops(p) do if p[d][2]>1 or p[d][1]=j then ok:=0; break; fi;

%p if not type((n+j)/(p[d][1]-j),integer) then ok:=0; break; fi; od;

%p if ok=1 then print(n); fi; fi; od; end: A225716(10^9,-6);

%Y Cf. A208728, A225702-A225715, A225717-A225720.

%K nonn

%O 1,1

%A _Paolo P. Lava_, May 13 2013

%E a(14)-a(25) from _Donovan Johnson_, Nov 15 2013