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A072389 Numbers of the form x*(x+1) * y*(y+1) ("bipronics") with x and y nonnegative integers. 7
0, 4, 12, 24, 36, 40, 60, 72, 84, 112, 120, 144, 180, 220, 240, 252, 264, 312, 336, 360, 364, 400, 420, 432, 480, 504, 540, 544, 600, 612, 660, 672, 684, 760, 792, 840, 864, 900, 924, 936, 1012, 1080, 1092, 1104, 1120, 1200, 1260, 1300, 1320 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
EXAMPLE
a(3) = 1*2*2*3 = 12.
CROSSREFS
Cf. A053990 (sequence of bipronics with x and y distinct).
Cf. A085780 (one quarter of this).
Sequence in context: A008077 A301265 A285350 * A218391 A297568 A353795
KEYWORD
nonn,easy
AUTHOR
Stuart M. Ellerstein (ellerstein(AT)aol.com), Jul 20 2002
EXTENSIONS
More terms from James A. Sellers, Jul 23 2002
STATUS
approved

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Last modified May 17 23:39 EDT 2024. Contains 372608 sequences. (Running on oeis4.)