A397093 - OEIS

%I #13 Jul 17 2026 09:19:34

%S 0,1,3,7,9,11,13,25,27,41,43,49,57,81,97,105,111,127,131,157,161,191,

%T 193,219,243,259,345,379,385,395,411,435,469,495,499,511,601,641,729,

%U 769,803,867,935,949,963,981,1015,1029,1135,1187,1257,1335,1405,1537

%N Nonnegative numbers with palindromic canonical snowball representation.

%C See A397794 for the definition of the canonical snowball representation of a number.

%H Rémy Sigrist, <a href="/A397093/b397093.txt">Table of n, a(n) for n = 1..10000</a>

%H Rémy Sigrist, <a href="/A397093/a397093.gp.txt">PARI program</a>

%e The first terms, alongside their canonical snowball representation, are:

%e   n   a(n)  snowball(a(n))

%e   --  ----  --------------

%e    1     0

%e    2     1               1

%e    3     3              11

%e    4     7             101

%e    5     9             111

%e    6    11             121

%e    7    13            1001

%e    8    25           10001

%e    9    27            1111

%e   10    41            1221

%e   11    43           10101

%e   12    49          100001

%e   13    57           11011

%e   14    81           11111

%e   15    97         1000001

%o (PARI) \\ See Links section.

%Y Cf. A046807, A397794.

%K nonn,base,new

%O 1,3

%A _Rémy Sigrist_, Jul 14 2026