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.

A256085 Non-palindromic balanced numbers in base 5.

This page as a plain text file.
%I A256085 #9 Nov 04 2024 18:17:46
%S A256085 140,170,202,232,266,296,328,358,392,422,454,484,518,548,635,660,685,
%T A256085 710,735,765,790,815,840,865,877,895,902,920,927,945,952,970,977,995,
%U A256085 1007,1032,1057,1082,1107,1128,1137,1153,1162,1178,1187,1203,1212,1228,1237,1261,1270,1286,1295,1311,1320,1336,1345,1361,1370
%N A256085 Non-palindromic balanced numbers in base 5.
%C A256085 Here a number is called balanced if the sum of digits weighted by their arithmetic distance from the "center" is zero. Since palindromes (A029952) are trivially balanced, they are excluded here.
%C A256085 This is the base-5 variant of the decimal version A256075 invented by Eric Angelini. See there, and the base-2 version A256082, for further information and examples.
%H A256085 Robert Israel, <a href="/A256085/b256085.txt">Table of n, a(n) for n = 1..10000</a>
%p A256085 filter:= proc(n) local L, m,i;
%p A256085   L:= convert(n, base, 5);
%p A256085   m:= (1+nops(L))/2;
%p A256085 add(L[i]*(i-m), i=1..nops(L))=0  and L <> ListTools:-Reverse(L)
%p A256085 end proc:
%p A256085 select(filter, [$1..10000]); # _Robert Israel_, Nov 04 2024
%o A256085 (PARI) is(n,b=5,d=digits(n,b),o=(#d+1)/2)=!(vector(#d,i,i-o)*d~)&&d!=Vecrev(d)
%Y A256085 Cf. A256082 - A256089, A256075, A256080, A029952.
%K A256085 nonn,base
%O A256085 1,1
%A A256085 _M. F. Hasler_, Mar 14 2015