A337947 - OEIS

%I #15 Oct 05 2020 01:02:16

%S 5,11,16,17,18,20,26,27,28,32,35,38,39,40,41,43,45,46,51,53,55,56,57,

%T 58,63,65,67,70,71,72,74,75,76,78,79,80,81,82,87,89,93,95,96,98,99,

%U 100,101,102,103,104,105,106,109,110,111,112,117,118,119,121,123

%N Numbers that do not appear in the addition or multiplication table of A337946.

%H Peter Kagey, <a href="/A337947/b337947.txt">Table of n, a(n) for n = 1..10000</a>

%e The addition table of A337946(k) for k=1..5:

%e    + | 1 3  7 12 22

%e   ---+-------------

%e    1 | 2 4  8 13 23

%e    3 |   6 10 15 25

%e    7 |     14 19 29

%e   12 |        24 34

%e   22 |           44

%e The multiplication table of A337946(k) for k=1..5:

%e    * | 1 3  7  12  22

%e   ---+---------------

%e    1 | 1 3  7  12  22

%e    3 |   9 21  36  66

%e    7 |     49  84 154

%e   12 |        144 264

%e   22 |            484

%e Neither of these two tables contain 5, 11, 16, 17, 18, or 20. Since each row is strictly increasing, the rest of the two (infinite) tables do not contain these values either.

%Y Cf. A263995, A337657, A337658, A337946.

%K nonn

%O 1,1

%A _Peter Kagey_, Oct 02 2020