A356585 - OEIS

%I #30 Nov 19 2022 21:18:01

%S 1,1,2,16,198,2927,50060,979361,21645853,534381060,14590180163,

%T 436814197446,14235563000269,501817445873045,19029286646922723,

%U 772532087068933899,33434018751249535666,1536767964161539414904,74769012084248550773909

%N Number of decimal digits in the n-th Gosper hyperfactorial of n (A330716).

%C The 0th Gosper hyperfactorial is the usual factorial function.

%F a(n) = A055642(A330716(n)).

%e a(0)=1 since the 0th Gosper hyperfactorial (0!) has one decimal digit.

%e a(3)=16 since the 3rd Gosper hyperfactorial of 3 is 1952152956156672.

%t Floor[Table[1+Sum[Log10[k]*(k^n), {k, 1, n}], {n, 1, 18}]]

%o (PARI) a(n) = floor(sum(k=1, n, log(k)*k^n/log(10))) + 1; \\ _Michel Marcus_, Sep 27 2022

%Y Cf. A055642, A330716, A356586.

%K nonn,base

%O 0,3

%A _Greg Huber_, Aug 13 2022