...factorial(n) plus/minus 1 is semiprime
Is there an Oeis sequence dedicated to numbers n such that n!+1 and n!1 are both semiprime? An example is 20970
Infact 20970!+1 is semiprime and also 20970!1 is semi prime No the example is wrong 
This would be the intersection of [OEIS]078778[/OEIS] (n such that n!+1 is semiprime) and [OEIS]078781[/OEIS] (n such that n!1 is semiprime). There is no separate sequence (yet, as far as I can tell).

The first few terms are: 5, 8, 10, 13, 20, 24, 26, 34, 59, 392.
392!  1 = 78958785391722157 * P832. 392! + 1 = 32749 * P844. 
[QUOTE=enzocreti;555623]Is there an Oeis sequence dedicated to numbers n such that n!+1 and n!1 are both semiprime? An example is 20970
Infact 20970!+1 is semiprime and also 20970!1 is semi prime No the example is wrong[/QUOTE] Neither 20970!+1 nor 20970!1 is semiprime, 20970!+1 = 7778806327 * C81510, and 20970!1 = 4156001 * C81513 
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