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A004099 Sum of digits of Euler numbers.

%I A004099 #10 Oct 24 2023 19:32:10
%S A004099 1,1,1,2,5,7,7,11,17,25,13,29,29,34,46,38,41,61,61,65,62,70,85,74,83,
%T A004099 88,91,110,113,124,106,128,170,142,157,164,128,178,172,146,176,178,
%U A004099 178,209,206,214,247,218,263,268,235,335,284,259,295,254,278,295,283,254,308,313
%N A004099 Sum of digits of Euler numbers.
%H A004099 Chai Wah Wu, <a href="/A004099/b004099.txt">Table of n, a(n) for n = 0..10000</a>
%F A004099 a(n) = A007953(A000111(n)).
%p A004099 b:= proc(n, k) option remember; `if`(k=0,
%p A004099      `if`(n=0, 1, 0), b(n, k-1)+b(n-1, n-k))
%p A004099     end:
%p A004099 a:= proc(n) option remember;
%p A004099       add(i,i=convert(b(n$2), base, 10))
%p A004099     end:
%p A004099 seq(a(n), n=0..100);  # _Alois P. Heinz_, Apr 17 2023
%o A004099 (Python)
%o A004099 from itertools import accumulate, islice
%o A004099 def A004099_gen(): # generator of terms
%o A004099     yield from (1,1)
%o A004099     blist = (0,1)
%o A004099     while True:
%o A004099         blist = tuple(accumulate(reversed(blist),initial=0))
%o A004099         yield sum(int(d) for d in str(blist[-1]))
%o A004099 A004099_list = list(islice(A004099_gen(),30)) # _Chai Wah Wu_, Apr 17 2023
%Y A004099 Cf. A000111, A007953.
%K A004099 nonn,base
%O A004099 0,4
%A A004099 _N. J. A. Sloane_