A357327 a(n) is the unique nonnegative integer k <= A058084(n)/2 such that binomial(A058084(n),k) = n.

0, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 3, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 3, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 3, 1, 1, 1

Offset: 1

Author

Pontus von Brömssen, Sep 24 2022

Keywords

• nonn

Examples

			The first occurrence of 6 in Pascal's triangle is in row 4 = A058084(6) and binomial(4,2) = 6, so a(6) = 2.
		

Links

• Pontus von Brömssen, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A007318, A058084.

Programs

PARI

a(n) = my(k=0); while (!vecsearch(vector((k+2)\2, i, binomial(k, i-1)), n), k++); select(x->(x==n), vector((k+2)\2, i, binomial(k, i-1)), 1)[1] - 1; \\ Michel Marcus, Sep 24 2022

Formula

A007318(A058084(n),a(n)) = n.