A051247 Binary numbers d(1)...d(j) such that d(i) = d(j+1-i) for all but 4 values of i.

10, 12, 18, 22, 24, 28, 34, 36, 39, 40, 43, 46, 48, 53, 54, 57, 58, 60, 66, 68, 71, 74, 76, 79, 80, 83, 86, 88, 91, 94, 96, 101, 102, 104, 109, 110, 113, 114, 116, 121, 122, 124, 130, 132, 135, 136, 139, 141, 144, 147, 149, 154, 156

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• base

Comments

Each number becomes a palindrome by changing two digits.

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A051244, A050874.

Programs

Maple

filter:= proc(n) local L;
  L:= convert(n,base,2):
  nops(select(i -> L[i] = L[-i], [$1..nops(L)]))=nops(L)-4
end proc:
select(filter, [$1..1000]); # Robert Israel, Nov 10 2024

Extensions

Name corrected by Sean A. Irvine, Aug 20 2021

Name corrected by Robert Israel, Nov 10 2024