A050429 - OEIS

%I #9 Aug 17 2021 02:40:35

%S 32,96,160,176,208,224,288,304,312,368,400,456,464,480,544,560,568,

%T 572,592,600,604,632,656,672,688,696,752,784,840,848,864,880,904,932,

%U 936,944,964,968,976,992,1056,1072,1080,1084,1086,1104,1112,1116,1118,1128

%N Numbers for which in base 2 the least number of digits that can be removed to leave a base 2 palindromic number (beginning with 1) is 5.

%o (Python)

%o from itertools import combinations

%o def ok(n):

%o     b = bin(n)[2:]

%o     for digs_to_remove in range(6):

%o         for skip in combinations(range(len(b)), digs_to_remove):

%o             newb = "".join(b[i] for i in range(len(b)) if i not in skip)

%o             if len(newb) > 0 and newb[0] == '1' and newb == newb[::-1]:

%o                 return (digs_to_remove == 5)

%o     return False

%o print(list(filter(ok, range(1129)))) # _Michael S. Branicky_, Aug 15 2021

%K nonn,base

%O 1,1

%A _Clark Kimberling_

%E Data corrected and extended by _Sean A. Irvine_, Aug 15 2021