Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #15 May 14 2022 17:12:22
%S 0,0,0,2,0,-2,4,2,0,8,0,-8,8,0,-8,8,0,-8,16,8,0,16,8,0,16,8,0,26,0,
%T -26,20,-6,-32,14,-12,-38,32,6,-20,26,0,-26,20,-6,-32,38,12,-14,32,6,
%U -20,26,0,-26,52,26,0,46,20,-6,40,14,-12,58,32,6,52,26,0,46,20,-6,64,38,12,58,32,6,52,26,0,80,0,-80,56,-24,-104,32,-48
%N n - reversal of base 3 digits of n (written in base 10).
%C a(n) is even.
%H Indranil Ghosh, <a href="/A055947/b055947.txt">Table of n, a(n) for n = 0..20000</a>
%F a(n) = n - A030102(n).
%e For n = 5, the reversal of base 3 digits of n (written in base 10) is 7. So, a(5) = 5 - 7 = -2. - _Indranil Ghosh_, Feb 01 2017
%t Table[n-FromDigits[Reverse[IntegerDigits[n,3]],3],{n,0,90}] (* _Harvey P. Dale_, May 14 2022 *)
%o (PARI) a(n) = n - fromdigits(Vecrev(digits(n, 3)), 3); \\ _Michel Marcus_, Aug 09 2019
%Y Cf. A030102, A056965.
%K base,sign
%O 0,4
%A _Henry Bottomley_, Jul 18 2000