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A004789 Least k such that number of distinct prime divisors of the numbers in row k of Pascal's triangle is n. 2
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 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
A004788(a(n)) = n and A004788(m) != n for m < a(n). - Reinhard Zumkeller, Mar 15 2015
LINKS
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
Sequence in context: A129630 A026429 A086917 * A027435 A014666 A067852
KEYWORD
nonn
AUTHOR
STATUS
approved

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Last modified February 27 15:09 EST 2024. Contains 370376 sequences. (Running on oeis4.)