|
%I #16 Feb 19 2024 01:54:48
%S 13,52,364,4732,75712,1665664,56632576,2265303040,56632576000,
%T 2265303040000,56632576000000,2265303040000000,56632576000000000,
%U 2265303040000000000,56632576000000000000,2265303040000000000000
%N a(1) = 13; for n > 0, a(n+1) = a(n) * sum of digits of a(n).
%C After the 7th element, every second element has the same beginning. a(9+2k) = 40 * a(8+2k) = 40 * 25 * a(7+2k).
%t NestList[# Total[IntegerDigits[#]]&,13,20] (* _Harvey P. Dale_, Jan 08 2019 *)
%Y Cf. A047892.
%K easy,nonn,base
%O 1,1
%A Miklos SZABO (mike(AT)ludens.elte.hu)
|
