

A092249


Positions of the integers in the standard diagonal enumeration of the rationals (with the integers in the first column and diagonals moving up to the right).


0



1, 2, 4, 6, 10, 12, 18, 22, 28, 32, 42, 46, 58, 64, 72, 80, 96, 102, 120, 128, 140, 150, 172, 180, 200, 212, 230, 242, 270, 278, 308, 324, 344, 360, 384, 396, 432, 450, 474, 490, 530, 542, 584, 604, 628, 650, 696, 712, 754, 774, 806, 830, 882, 900, 940, 964
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OFFSET

1,2


COMMENTS

A002088 without the leading zero. [R. J. Mathar, Jul 20 2009]


LINKS

Table of n, a(n) for n=1..56.


EXAMPLE

The first few terms of the full enumeration are 1, 2, 1/2, 3, 1/3, 4, 3/2, 2/3, 1/4, 5, giving a(n) = 1, 2, 4, 6, 10,...
Contribution from R. J. Mathar, Jul 20 2009: (Start)
The positions in the first column of the table
....1..1/2..1/3..1/4..1/5..1/6..1/7..1/8..1/9.1/10.1/11.1/12
....2.......2/3.......2/5.......2/7.......2/9......2/11.....
....3..3/2.......3/4..3/5.......3/7..3/8......3/10.3/11.....
....4.......4/3.......4/5.......4/7.......4/9......4/11.....
....5..5/2..5/3..5/4.......5/6..5/7..5/8..5/9......5/11.5/12
....6.................6/5.......6/7................6/11.....
....7..7/2..7/3..7/4..7/5..7/6.......7/8..7/9.7/10.7/11.7/12
....8.......8/3.......8/5.......8/7.......8/9......8/11.....
....9..9/2.......9/4..9/5.......9/7..9/8......9/10.9/11.....
...10......10/3................10/7......10/9.....10/11.....
...11.11/2.11/3.11/4.11/5.11/6.11/7.11/8.11/911/10.....11/12
...12................12/5......12/7...............12/11.....
if scanned along rising antidiagonals, as defined by the ratios A038566(i)/A020653(i). (End)


CROSSREFS

Cf. A002088, A020653, A038566.
Sequence in context: A152919 A306564 A002088 * A019332 A002491 A045958
Adjacent sequences: A092246 A092247 A092248 * A092250 A092251 A092252


KEYWORD

nonn


AUTHOR

Andrew Niedermaier, Feb 20 2004


EXTENSIONS

a(11) and a(12) corrected by R. J. Mathar, Jul 20 2009
Incorrect recurrence formula removed by R. J. Mathar, Jul 29 2009
More terms (using A002088) from Michel Marcus, Sep 10 2018


STATUS

approved



