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A255265 Numbers representable as x*y*(x+y), where x>=y>1. 4
16, 30, 48, 54, 70, 84, 96, 120, 126, 128, 160, 162, 180, 198, 210, 240, 250, 264, 286, 308, 324, 330, 336, 384, 390, 420, 432, 448, 462, 468, 510, 520, 540, 546, 560, 576, 624, 630, 646, 660, 672, 686, 714, 720, 750, 768, 798, 810, 840, 880, 884, 912, 960, 966, 1008 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..55.

EXAMPLE

a(2) = 30 = 3*2*(3+2).

a(5) = 70 = 5*2*(5+2).

MATHEMATICA

r[n_] := Reduce[x >= y > 1 && n == x*y*(x+y), {x, y}, Integers]; Reap[For[n = 2, n <= 1000, n = n+2, If[r[n] =!= False, Print[n]; Sow[n]]]][[2, 1]] (* Jean-Fran├žois Alcover, Feb 26 2015 *)

PROG

(Python)

TOP = 10000

a = [0]*TOP

for y in range(2, TOP//2):

for x in range(y, TOP//2):

    k = x*y*(x+y)

    if k>=TOP: break

    a[k]+=1

[n for n in range(TOP) if a[n]>0]

CROSSREFS

Cf. A254671.

Sequence in context: A228664 A217715 A064634 * A183372 A308026 A145581

Adjacent sequences:  A255262 A255263 A255264 * A255266 A255267 A255268

KEYWORD

nonn

AUTHOR

Alex Ratushnyak, Feb 19 2015

STATUS

approved

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Last modified August 10 22:36 EDT 2022. Contains 356046 sequences. (Running on oeis4.)