A240972 Lexicographically earliest sequence such that (i) the binary plot of the sequence is symmetric with respect to the line y=x and (ii) the derived sequence (A000265(a(n))) contains only distinct terms.

1, 6, 10, 28, 72, 352, 240, 832, 672, 2432, 17408, 12800, 47104, 55296, 41984, 126976, 950272, 2162688, 2424832, 3211264, 18350080, 5111808, 90177536, 377487360, 55574528, 394264576, 247463936, 3422552064, 578813952, 14763950080

Offset: 1

Author

Paul Tek, Aug 05 2014

Keywords

• nonn
• base
• nice
• look

Comments

The first constraint means that writing the binary representation of each number vertically yields a symmetrical plot about the line y = x (see the binary plot).

The second constraint ensures that the sequence contains only distinct terms, and differs from A000079.

The keywords "nice" and "look" are based on the fact that the binary plot is very interesting. - N. J. A. Sloane, Aug 22 2014

Links

• Paul Tek, Table of n, a(n) for n = 1..3313
• Paul Tek, Binary plot of the first hundred terms
• Paul Tek, Perl program for this sequence
• Eric Weisstein's World of Mathematics, Binary Plot

Crossrefs

Cf. A230598, A240992 (odd part).

Programs

Perl

See Link section.