A180058 Smallest number occurring in exactly n rows of Pascal's triangle.

2, 6, 120, 3003

Offset: 1

Author

Reinhard Zumkeller, Dec 24 2012

Keywords

• nonn
• more

Comments

A059233(a(n)) = n and A059233(m) < n for m < a(n).

Examples

			.  n  A180058  referred equal binomial coefficients (A007318)  A059233
.  -  -------  ----------------------------------------------  -------
.  1        2   C (2, 1)                                             1
.  2        6   C (4, 2)   C (6, 1)                                  2
.  3      120   C (10, 3)  C (16, 2)  C (120, 1)                     3
.  4     3003   C (14, 6)  C (15, 5)  C (78, 2)   C (3003, 1)        4 .
		

Links

• Wikipedia, Singmaster's conjecture
• Index entries for triangles and arrays related to Pascal's triangle

Crossrefs

Cf. A185024, A182237, A098565, A003015, A003016.

Programs

Haskell

import Data.List (elemIndex)
import Data.Maybe (fromJust)
a180058 = (+ 2) . fromJust . (`elemIndex` a059233_list)