A077342 First column of A077341.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 200, 21, 22, 23, 24, 25, 26, 27, 28, 29, 300, 310, 32, 33, 34, 35, 36, 37, 38, 39, 400, 410, 420, 43, 44, 45, 46, 47, 48, 49, 500, 510, 520, 530, 54, 55, 56, 57, 58, 59, 600, 610, 620, 630, 640, 65, 66, 67

Offset: 1

Author

Amarnath Murthy, Nov 05 2002

Keywords

• base
• easy
• nonn

Comments

a(20) = 200 and not 20. Can anyone derive a formula for a(n)?

a(n) = n when n > 10 * floor(n/10) + floor(n/10) - 2. Otherwise it is guaranteed that n has appeared in a previous row of the triangle. - Alonso del Arte, Jan 07 2013

Links

• Hans Havermann, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A077339, A077340, A077341, A077343.