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A027384 Number of distinct products ij with 0 <= i, j <= n. 10
1, 2, 4, 7, 10, 15, 19, 26, 31, 37, 43, 54, 60, 73, 81, 90, 98, 115, 124, 143, 153, 165, 177, 200, 210, 226, 240, 255, 268, 297, 309, 340, 355, 373, 391, 411, 424, 461, 481, 502, 518, 559, 576, 619, 639, 660, 684, 731, 748, 779, 801, 828, 851, 904, 926, 957, 979, 1009, 1039 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

a(n) = A027420(n,0) = A027420(n,n). - Reinhard Zumkeller, May 02 2014

LINKS

T. D. Noe, Table of n, a(n) for n = 0..1000

MAPLE

A027384 := proc(n)

    local L, i, j ;

    L := {};

    for i from 0 to n do

        for j from i to n do

            L := L union {i*j};

        end do:

    end do:

    nops(L);

end proc: # R. J. Mathar, May 06 2016

MATHEMATICA

u = {}; Table[u = Union[u, n*Range[0, n]]; Length[u], {n, 0, 100}] (* T. D. Noe, Jan 07 2012 *)

PROG

(Haskell)

import Data.List (nub)

a027384 n = length $ nub [i*j | i <- [0..n], j <- [0..n]]

-- Reinhard Zumkeller, Jan 01 2012

CROSSREFS

Equals A027424 + 1, n>0.

Cf. A027417, A027427, A027425.

Sequence in context: A171930 A276164 A095116 * A022939 A036702 A007983

Adjacent sequences:  A027381 A027382 A027383 * A027385 A027386 A027387

KEYWORD

nonn,easy

AUTHOR

Fred Schwab (fschwab(AT)nrao.edu)

STATUS

approved

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Last modified February 22 21:02 EST 2018. Contains 299469 sequences. (Running on oeis4.)