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 A076302 Triangle T(n,k) = number of k-smooth divisors of n, read by rows. 0
 1, 1, 2, 1, 1, 2, 1, 3, 3, 3, 1, 1, 1, 1, 2, 1, 2, 4, 4, 4, 4, 1, 1, 1, 1, 1, 1, 2, 1, 4, 4, 4, 4, 4, 4, 4, 1, 1, 3, 3, 3, 3, 3, 3, 3, 1, 2, 2, 2, 4, 4, 4, 4, 4, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 3, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 2, 4, 4, 4, 4, 4, 4, 4, 4 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Eric Weisstein's World of Mathematics, Divisor Function. Eric Weisstein's World of Mathematics, Smooth Number. FORMULA T(n,n) = A000005(n); T(n,2) = A001511(n) for n>1. T(n,3) = A072078(n) for n>2. EXAMPLE Triangle begins:                    1                  1   2                1   1   2              1   3   3   3            1   1   1   1   2          1   2   4   4   4   4        1   1   1   1   1   1   2      1   4   4   4   4   4   4   4    1   1   3   3   3   3   3   3   3 MATHEMATICA T[n_, k_] := Times@@(IntegerExponent[n, #]+1& /@ Select[Range[2, k], PrimeQ]); Table[T[n, k], {n, 1, 14}, {k, 1, n}] // Flatten (* Jean-François Alcover, Sep 15 2021 *) CROSSREFS Cf. A000005, A001511, A072078. Sequence in context: A239000 A105248 A289495 * A104524 A233322 A233324 Adjacent sequences:  A076299 A076300 A076301 * A076303 A076304 A076305 KEYWORD nonn,tabl,changed AUTHOR Reinhard Zumkeller, Mar 14 2003 STATUS approved

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Last modified September 25 12:38 EDT 2021. Contains 347654 sequences. (Running on oeis4.)