A104618 Write the natural numbers in base 15 in a triangle with k digits in the k-th row, as shown below. Sequence gives the leading diagonal.

1, 3, 6, 10, 1, 1, 6, 10, 2, 2, 10, 1, 3, 4, 7, 0, 5, 6, 12, 7, 8, 8, 10, 7, 11, 12, 1, 0, 1, 1, 1, 1, 1, 3, 1, 1, 5, 1, 1, 8, 1, 1, 11, 1, 1, 14, 2, 2, 2, 2, 2, 5, 2, 2, 9, 2, 2, 13, 2, 3, 2, 3, 3, 6, 3, 3, 10, 3, 3, 0, 4, 4, 5, 4, 4, 10, 4, 4, 0, 5, 5, 5, 5, 5, 11, 5, 6, 2, 6, 6, 8, 6, 6, 14, 7, 7, 5, 7, 7

Offset: 1

Author

Robert G. Wilson v, Mar 16 2005

Keywords

• base
• nonn

Comments

1

23

456

789A

BCDE1

011121...

Crossrefs

Cf. A104606, A104607, A104608, A104609, A104610, A104611, A104612, A104613, A091425, A104614, A104615, A104616, A104617, A104619, A104620.

Programs

Mathematica

t = Flatten[ IntegerDigits[ Range[1900], 15]]; t[[Table[n(n + 1)/2, {n, 100}]]]