A333234 Nonprimes describing the nonprime digits' positions in a way explained in the Comments section.

20, 40, 34, 64, 76, 84, 200, 106, 300, 118, 210, 270, 248, 124, 140, 324, 221, 231, 261, 338, 150, 170, 186, 364, 384, 341, 390, 371, 424, 451, 161, 481, 506, 511, 548, 570, 600, 551, 581, 611, 628, 636, 656, 664, 688, 714, 694, 749, 721, 750, 794

Offset: 1

Author

Eric Angelini and Carole Dubois, Mar 12 2020

Keywords

• base
• nonn

Comments

"20" must be read: "At position 2, there is a 0". And indeed, there is, when considering the sequence as a string of concatenated digits;

"40" reads: "At position 4, there is a 0" - which is true;

"34" reads: "At position 3, there is a 4" - which is also true;

...

"200" reads: "At position 20, there is a 0" - which is true (the central 0 in 300); etc.

Links

• Carole Dubois, Table of n, a(n) for n = 1..4103

Crossrefs

Cf. A264646.