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A027429 Number of distinct products ijk with 0 <= i<j<k <= n. 4
0, 0, 1, 2, 5, 11, 17, 30, 43, 61, 76, 112, 127, 178, 207, 239, 275, 362, 397, 508, 555, 614, 678, 839, 884, 1005, 1093, 1199, 1278, 1530, 1591, 1882, 1999, 2134, 2276, 2433, 2519, 2922, 3097, 3279, 3392, 3885, 4015, 4564, 4751, 4939, 5187, 5841, 5988, 6423 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

T. D. Noe, Table of n, a(n) for n=0..200

FORMULA

a(n) = A027430(n)+1. - T. D. Noe, Jan 16 2007

EXAMPLE

a(3) = 2 (0 and 6 being the only products) and a(4)=5 (with products 0,6,8,12 and 24).

MATHEMATICA

nn=50; prod=Table[0, {1+nn^3}]; t=Table[Do[prod[[1+i*j*k]]=1, {i, 0, n}, {j, i+1, n}, {k, j+1, n}]; Count[Take[prod, 1+n^3], 1], {n, 0, nn}] - T. D. Noe, Jan 16 2007

PROG

(Haskell)

import Data.List (nub)

a027429 n = length $ nub [i*j*k | k<-[2..n], j<-[1..k-1], i<-[0..j-1]]

-- Reinhard Zumkeller, Jan 01 2012

CROSSREFS

Cf. A027425, A027426, A027427, A027430.

Sequence in context: A055499 A014424 A023228 * A059987 A027426 A133928

Adjacent sequences:  A027426 A027427 A027428 * A027430 A027431 A027432

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

Corrected by T. D. Noe, Jan 16 2007

STATUS

approved

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Last modified March 22 01:06 EDT 2019. Contains 321406 sequences. (Running on oeis4.)