A327887 Infinite sequence of signed integers where each is chosen to be as small as possible (in absolute value) subject to the condition that for every k >= 1, all the k(k+1)/2 numbers in the triangle of differences of the first k terms are distinct; in case of a tie, preference is given to the positive value.

1, -1, 2, -3, 4, -6, 8, -4, 6, -9, 16, -7, 19, -11, 17, -14, 9, -28, 11, -16, 13, -20, 15, -19, 18, -18, 27, -24, 31, -21, 30, -35, 38, -32, 21, -46, 32, -22, 44, -40, 34, -38, 46, -39, 36, -41, 47, -43, 42, -44, 43, -55, 50, -42, 52, -45, 57, -53, 62, -57, 59

Offset

1,3

Comments

This sequence is a signed variant of A327460.

Links

Rémy Sigrist, Table of n, a(n) for n = 1..5000

Rémy Sigrist, C# program for A327887

Formula

Apparently, abs(a(n)) ~ n as n tends to infinity.

Example

The difference table for the first 8 terms is:
     1    -1     2   -3    4   -6    8  -4 ...
       -2     3    -5    7  -10   14  -12 ...
           5    -8    12  -17   24  -26 ...
            -13    20   -29   41  -50 ...
                33   -49    70  -91 ...
                  -82   119  -161 ...
                     201  -280 ...
                       -481 ...
                          ...

Prog

(C#) See Links section.

Crossrefs

Cf. A327460.

Sequence in context: A351329 A152306 A120817 * A339361 A166310 A293030

Adjacent sequences: A327884 A327885 A327886 * A327888 A327889 A327890

Keyword

sign

Author

Rémy Sigrist, Sep 29 2019

Status

approved