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.

A256088 Non-palindromic balanced numbers in base 8.

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%I A256088 #9 Nov 04 2024 18:17:25
%S A256088 536,608,680,706,752,778,824,850,899,922,971,994,1049,1072,1121,1144,
%T A256088 1193,1219,1265,1291,1337,1363,1412,1435,1484,1507,1562,1585,1634,
%U A256088 1657,1706,1732,1778,1804,1850,1876,1925,1948,1997
%N A256088 Non-palindromic balanced numbers in base 8.
%C A256088 Here a number is called balanced if the sum of digits weighted by their arithmetic distance from the "center" is zero. Since palindromes (A029803) are trivially balanced, they are excluded here.
%C A256088 This is the base-8 variant of the decimal version A256075 invented by Eric Angelini. See there, and the base-2 version A256082, for further information and examples.
%H A256088 Robert Israel, <a href="/A256088/b256088.txt">Table of n, a(n) for n = 1..10000</a>
%p A256088 filter:= proc(n) local L, m,i;
%p A256088   L:= convert(n, base, 8);
%p A256088   m:= (1+nops(L))/2;
%p A256088 add(L[i]*(i-m), i=1..nops(L))=0  and L <> ListTools:-Reverse(L)
%p A256088 end proc:
%p A256088 select(filter, [$1..10000]); # _Robert Israel_, Nov 04 2024
%o A256088 (PARI) is(n,b=8,d=digits(n,b),o=(#d+1)/2)=!(vector(#d,i,i-o)*d~)&&d!=Vecrev(d)
%Y A256088 Cf. A256082 - A256089, A256075, A256080, A029803.
%K A256088 nonn,base
%O A256088 1,1
%A A256088 _M. F. Hasler_, Mar 14 2015