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A223881 Denominators in the expression m!/(prime(m-1)+1) for m > 1 such that this expression is not an integer. 2

%I #39 Mar 16 2024 11:20:48

%S 3,2,19,31,37,79,41,97,53,139,71,157,83,199,211,229,131,271,137,307,

%T 331,337,173,367,379,197,439,227,499,263,547,281,577,293,197,199,601,

%U 607,619,661,227,229,691,239,727,383,269,811,829,283,431,877,467,937,313

%N Denominators in the expression m!/(prime(m-1)+1) for m > 1 such that this expression is not an integer.

%C It appears that all terms are primes.

%H Paolo P. Lava, <a href="/A223881/b223881.txt">Table of n, a(n) for n = 1..1000</a>

%t Denominator[Select[Table[m!/(Prime[m - 1] + 1), {m, 2, 300}], ! IntegerQ[#] &]] (* _T. D. Noe_, May 03 2013 *)

%o (PARI) m=M=1;forprime(p=2,1e5,M*=m++;t=denominator(M/(p+1)); if(t>1, print1(t", "))) \\ _Charles R Greathouse IV_, May 08 2013

%Y Cf. A007528, A024898, A002476, A091178.

%K nonn

%O 1,1

%A _Alexander R. Povolotsky_, May 01 2013

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Last modified April 25 04:42 EDT 2024. Contains 371964 sequences. (Running on oeis4.)