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

2, 6, 120, 3003

Offset

1,1

Comments

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

Links

Table of n, a(n) for n=1..4.

Wikipedia, Singmaster's conjecture

Index entries for triangles and arrays related to Pascal's triangle

Example

.  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 .

Prog

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

Crossrefs

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

Sequence in context: A075391 A212158 A058251 * A264470 A039716 A164955

Adjacent sequences: A180055 A180056 A180057 * A180059 A180060 A180061

Keyword

nonn,more

Author

Reinhard Zumkeller, Dec 24 2012

Status

approved