cp's OEIS Frontend

A349403 Sum of the digits of Sum_{k=1..n} k!.

%I A349403 #24 Nov 19 2021 07:26:20
%S A349403 0,1,3,9,6,9,18,18,18,18,27,36,36,54,54,36,45,45,72,72,63,81,99,99,
%T A349403 117,108,99,126,126,144,117,162,144,153,171,171,153,180,180,198,171,
%U A349403 225,207,252,225,261,261,252,270,234,270,261,279,324,324,306,342,333,333,297,351,360,351,333,387,405,369
%N A349403 Sum of the digits of Sum_{k=1..n} k!.
%C A349403 If n > 4, then 9 divides a(n).
%F A349403 a(n) = A007953(A007489(n)).
%F A349403 a(n) = A127554(n+1) - 1 for n > 3.
%e A349403    n |  A007489 | A003422 | a(n) | A127554 |
%e A349403 -----+----------+---------+------+---------+
%e A349403    0 |        0 |       0 |    0 |       0 |
%e A349403    1 |        1 |       1 |    1 |       1 |
%e A349403    2 |        3 |       2 |    3 |       2 |
%e A349403    3 |        9 |       4 |    9 |       4 |
%e A349403    4 |       33 |      10 |    6 |       1 |
%e A349403    5 |      153 |      34 |    9 |       7 |
%e A349403    6 |      873 |     154 |   18 |      10 |
%e A349403    7 |     5913 |     874 |   18 |      19 |
%e A349403    8 |    46233 |    5914 |   18 |      19 |
%e A349403    9 |   409113 |   46234 |   18 |      19 |
%e A349403   10 |  4037913 |  409114 |   27 |      19 |
%e A349403   11 | 43954713 | 4037914 |   36 |      28 |
%t A349403 Table[Total[IntegerDigits[Sum[k!,{k,n}]]],{n,0,66}] (* _Stefano Spezia_, Nov 16 2021 *)
%o A349403 (PARI) a(n) = sumdigits(sum(k=1, n, k!));
%Y A349403 Cf. A004152, A007489, A007953, A127554.
%K A349403 nonn,base
%O A349403 0,3
%A A349403 _Seiichi Manyama_, Nov 15 2021