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.
%I A284800 #12 Apr 01 2020 17:52:24 %S A284800 6,9,12,78,90,102,114,141,153,165,177,204,216,228,240,1086,1134,1182, %T A284800 1230,1338,1386,1434,1482,1590,1638,1686,1734,1842,1890,1938,1986, %U A284800 2109,2157,2205,2253,2361,2409,2457,2505,2613,2661,2709,2757,2865,2913,2961,3009,3132 %N A284800 Fixed points of the transform A284799. %C A284800 All terms are divisible by 3. - _Robert Israel_, Apr 01 2020 %H A284800 Robert Israel, <a href="/A284800/b284800.txt">Table of n, a(n) for n = 1..5000</a> %e A284800 78 is a term of the sequence because 78 in base 4 is 1032, its complement in base 4 is 2301 and the digit reverse is again 1032 that is 78 in base 10. %p A284800 P:=proc(q,h) local a,b,k,n; for n from 1 to q do a:=convert(n,base,h); b:=0; %p A284800 for k from 1 to nops(a) do a[k]:=h-1-a[k]; b:=h*b+a[k]; od; if b=n then print(n); fi; od; end: P(10^2,4); %Y A284800 Cf. A035928, A284799. %K A284800 nonn,base,easy %O A284800 1,1 %A A284800 _Paolo P. Lava_, Apr 03 2017