# [seqfan] Re: Conway's subprime Fibonacci sequences

Wouter Meeussen wouter.meeussen at telenet.be
Sun Jul 29 18:12:39 CEST 2012

```Hans,

anti-diagonal (up) see https://oeis.org/A073189/a073189.txt:
{1}, {2, 3}, {4, 5, 6}, {7, 8, 9, 10}, ..

as index-pairs: {row,col} :

{1, 1},
{2, 1}, {1, 2},
{3, 1}, {2, 2}, {1, 3},
...

as in

a      c      f
|   /       /
b      e
/
d

see? they cover the whole square array.
Your two examples are limited to the upper or lower triangular half of it,
and it ain't symmetric.

Wouter.

-----Original Message-----
From: Hans Havermann
Sent: Sunday, July 29, 2012 5:19 PM
To: Sequence Fanatics Discussion list
Subject: [seqfan] Re: Conway's subprime Fibonacci sequences

> So submit the cycle lengths ordered by the first starting pair that
> generates that cycle (in anti-diagonal order).

Wouter Meeussen:

> In selecting the starting points for each cycle, I followed Franklin
> T. Adams-Watters' suggestion of ordering the pairs in anti-diagonal
> order.

I have to betray my ignorance of not knowing what 'anti-diagonal
order' meant exactly. In trying to figure it out (for positive
integers), I conjectured that it is either {{1,1}, {1,2}, {2,2},
{1,3}, {2,3}, {3,3}, {1,4}, ...} or {{1,1}, {2,1}, {2,2}, {3,1},
{3,2}, {3,3}, {4,1}, ...}. But Wouter's A214892-A214896 appears to
employ two from the former ({10,18}, {23,162}} and three from the
latter ({4,1}, {18,5}, {382,127}). So I'm still confused.

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