cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A117789 Lucas numbers which are divisible by the sum of their digits.

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%I A117789 #10 Feb 08 2021 02:54:22
%S A117789 1,3,4,7,18,322,5778,505019158607,84722519070079276,
%T A117789 1473646213395791149646646123,
%U A117789 105249261265075663875711417309855979021650214636
%N A117789 Lucas numbers which are divisible by the sum of their digits.
%C A117789 a(12) has 83 digits and it is too large to include in the data section. - _Amiram Eldar_, Feb 08 2021
%H A117789 Amiram Eldar, <a href="/A117789/b117789.txt">Table of n, a(n) for n = 1..17</a>
%F A117789 a(n) = A000204(A337449(n+1)). - _Amiram Eldar_, Feb 08 2021
%e A117789 322 is in the sequence because it is a Lucas number and it is divisible by the sum of its digits, 3+2+2 = 7.
%t A117789 Select[LinearRecurrence[{1, 1}, {1, 3}, 230], Divisible[#, Plus @@ IntegerDigits[#]] &] (* _Amiram Eldar_, Feb 08 2021 *)
%o A117789 (PARI) {m=370;a=1;b=3;print1(a,",",b,",");for(n=3,m,c=b+a;a=b;b=c;s=0;k=b;while(k>0,d=divrem(k,10);k=d[1];s=s+d[2]);if(b%s==0,print1(b,",")))} \\ _Klaus Brockhaus_, Apr 17 2006
%Y A117789 Intersection of A000204 and A005349.
%Y A117789 Cf. A337449.
%K A117789 base,nonn
%O A117789 1,2
%A A117789 Luc Stevens (lms022(AT)yahoo.com), Apr 15 2006
%E A117789 a(9) corrected, a(10) and a(11) from _Klaus Brockhaus_, Apr 17 2006