A110339 Triangular array read by rows: the n-th row contains the first n multiples of n not included earlier that are coprime to n-1 and n+1.

1, 2, 4, 3, 9, 15, 8, 16, 28, 32, 5, 25, 35, 55, 65, 6, 12, 18, 24, 36, 48, 7, 49, 77, 91, 119, 133, 161, 40, 64, 80, 88, 104, 128, 136, 152, 27, 63, 81, 99, 117, 153, 171, 189, 207, 10, 20, 50, 70, 100, 130, 140, 160, 170, 190, 11, 121, 143, 187, 209, 253, 319, 341, 407, 451, 473, 60, 72, 84, 96, 108, 120, 144, 168, 180, 192, 204, 216, 13, 169

Offset

1,2

Links

Table of n, a(n) for n=1..80.

Example

1
2 4
3 9 15
8 16 28 32
5 25 35 55 65 (45 skipped as 45 is not coprime to 6).
6 12 18 24 36 48
...

Crossrefs

Cf. A110340, A110341.

Sequence in context: A285268 A100781 A358488 * A223703 A157406 A075363

Adjacent sequences: A110336 A110337 A110338 * A110340 A110341 A110342

Keyword

easy,nonn,tabl

Author

Amarnath Murthy, Jul 20 2005

Extensions

Corrected definition and more terms. - David Wasserman, Nov 19 2008

Status

approved