A051247 - OEIS

%I #14 Nov 10 2024 09:24:53

%S 10,12,18,22,24,28,34,36,39,40,43,46,48,53,54,57,58,60,66,68,71,74,76,

%T 79,80,83,86,88,91,94,96,101,102,104,109,110,113,114,116,121,122,124,

%U 130,132,135,136,139,141,144,147,149,154,156

%N Binary numbers d(1)...d(j) such that d(i) = d(j+1-i) for all but 4 values of i.

%C Each number becomes a palindrome by changing two digits.

%H Robert Israel, <a href="/A051247/b051247.txt">Table of n, a(n) for n = 1..10000</a>

%p filter:= proc(n) local L;

%p   L:= convert(n,base,2):

%p   nops(select(i -> L[i] = L[-i], [$1..nops(L)]))=nops(L)-4

%p end proc:

%p select(filter, [$1..1000]); # _Robert Israel_, Nov 10 2024

%Y Cf. A051244, A050874.

%K nonn,base

%O 1,1

%A _Clark Kimberling_

%E Name corrected by _Sean A. Irvine_, Aug 20 2021

%E Name corrected by _Robert Israel_, Nov 10 2024