cp's OEIS Frontend

A084229 Let b(1)=1, b(2)=2, b(n) = sum of digits of b(1)+b(2)+b(3)+...+b(n-1), sequence gives values of n such that b(n)=3.

%I A084229 #31 Oct 16 2024 21:20:36
%S A084229 3,5,7,9,17,19,27,29,87,95,97,159,591,599,601,663,1143,4609,4617,4619,
%T A084229 4681,5161,8993,13165,38277,38279,38341,38821,42653,46825,75043,79223,
%U A084229 327015,327023,327025,327087,327567,331399,335571,363789,367969,642981,647153,2847029,2847031,2847093,2847573
%N A084229 Let b(1)=1, b(2)=2, b(n) = sum of digits of b(1)+b(2)+b(3)+...+b(n-1), sequence gives values of n such that b(n)=3.
%C A084229 The {b(n)} sequence is A084228. - _N. J. A. Sloane_, Jun 26 2014
%C A084229 Note that b(k)==0 (mod 3) for n>2.
%H A084229 Robert G. Wilson v, <a href="/A084229/b084229.txt">Table of n, a(n) for n = 1..107</a>
%F A084229 Conjecture : a(n)/n^3 is bounded.
%t A084229 k = 3; lst = {}; a = 3; While[k < 100000001, b = a + Total@ IntegerDigits@ a; If[b == a + 3, AppendTo[lst, k]; Print@ k]; a = b; k++]; lst (* _Robert G. Wilson v_, Jun 27 2014 *)
%o A084229 (PARI) upto(n)={my(L=List(), s=3, k=3); while(k<=n, my(t=sumdigits(s)); if(t==3, listput(L,k)); s+=t; k++); Vec(L)} \\ _Andrew Howroyd_, Oct 16 2024
%Y A084229 Cf. A065075, A084228.
%K A084229 base,nonn
%O A084229 1,1
%A A084229 _Benoit Cloitre_, Jun 21 2003
%E A084229 a(23) onward from _Robert G. Wilson v_, Jun 27 2014