A004789 Least k such that number of distinct prime divisors of the numbers in row k of Pascal's triangle is n.

0, 2, 4, 6, 10, 11, 16, 18, 22, 23, 29, 35, 39, 42, 44, 47, 55, 59, 62, 69, 71, 78, 79, 83, 89, 100, 102, 104, 107, 111, 119, 130, 131, 138, 139, 149, 153, 159, 164, 167, 174, 179, 181, 191, 194, 197, 199, 215, 223, 228, 230, 233, 239, 250, 251, 259, 263, 269, 272, 279, 282

Offset

0,2

Comments

A004788(a(n)) = n and A004788(m) != n for m < a(n). - Reinhard Zumkeller, Mar 15 2015

Links

Reinhard Zumkeller, Table of n, a(n) for n = 0..250

Prog

(PARI) a(n) = {irow = 0; while(omega(prod(i=0, irow, binomial(irow, i)))!=n, irow++); return (irow); } \\ Michel Marcus, May 13 2013
(Haskell)
import Data.List (elemIndex); import Data.Maybe (fromJust)
a004789 = fromJust . (`elemIndex` a004788_list)
-- Reinhard Zumkeller, Mar 15 2015

Crossrefs

Cf. A004788, A256113.

Sequence in context: A129630 A026429 A086917 * A027435 A014666 A067852

Adjacent sequences: A004786 A004787 A004788 * A004790 A004791 A004792

Keyword

nonn

Author

Clark Kimberling

Status

approved