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A139174 a(n) = (n!-4)/4. 12

%I #29 Sep 08 2022 08:45:33

%S 5,29,179,1259,10079,90719,907199,9979199,119750399,1556755199,

%T 21794572799,326918591999,5230697471999,88921857023999,

%U 1600593426431999,30411275102207999,608225502044159999

%N a(n) = (n!-4)/4.

%C In the solution set of the equation, n! + s^2 = m^2, for any n>=4 the maximum value of s is (n!-4)/4. - _Sudipta Mallick_, Jul 27 2019

%H Sudipta Mallick, <a href="/A139174/b139174.txt">Table of n, a(n) for n = 4..400</a> (terms 4..300 from Vincenzo Librandi)

%F a(n) = numerator(((n+2)!-4)/(7*(n+2)!)), with offset 2. [_Gary Detlefs_, Nov 07 2010]

%F E.g.f.: -exp(x)-(12+x^2*(-6+(-4+x)*x))/(12*(-1+x)). - _Stefano Spezia_, Sep 08 2019

%t Table[(n! - 4)/4, {n, 4, 20}]

%o (Magma) [(Factorial(n)-4)/4: n in [4..25]]; // _Vincenzo Librandi_, Jul 20 2011

%Y Cf. A033312, A139172, A139173, A139174, A139175, A139176, A139177, A139183, A139184.

%K nonn,easy

%O 4,1

%A _Artur Jasinski_, Apr 11 2008

%E Definition corrected by _Gary Detlefs_, Nov 07 2010

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Last modified April 24 22:17 EDT 2024. Contains 371964 sequences. (Running on oeis4.)