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A332842 Initial digit of n-th superfactorial.

%I A332842 #20 Mar 21 2020 16:02:43
%S A332842 1,1,2,1,2,3,2,1,5,1,6,2,1,7,6,9,1,6,4,5,1,6,7,1,1,1,7,7,2,2,5,4,1,1,
%T A332842 3,3,1,1,8,1,1,4,6,4,1,1,7,1,2,1,4,6,5,2,5,6,4,1,4,6,5,2,8,1,2,1,9,3,
%U A332842 8,1,1,1,9,4,1,3,6,9,1,9,6,3,1,7,2,6,1,3,6,1,1,2,2,3,3,3,3,3,3,2,2
%N A332842 Initial digit of n-th superfactorial.
%H A332842 Chai Wah Wu, <a href="/A332842/b332842.txt">Table of n, a(n) for n = 0..10000</a>
%F A332842 a(n) = A000030(A000178(n)).
%e A332842 a(6) = 2 because A000178(6) = 24883200.
%o A332842 (PARI) a(n) = digits(prod(k=2, n, k!))[1]; \\ _Michel Marcus_, Feb 26 2020
%o A332842 (Python)
%o A332842 def A332842(n):
%o A332842     m, k = 1, 1
%o A332842     for i in range(2,n+1):
%o A332842         k *= i
%o A332842         m *= k
%o A332842     return int(str(m)[0]) # _Chai Wah Wu_, Mar 17 2020
%Y A332842 Cf. A000030, A000178, A008905.
%K A332842 easy,nonn,base
%O A332842 0,3
%A A332842 _Eder Vanzei_, Feb 26 2020