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A126695 Numbers that can be expressed as the ratio between the product and the sum of n consecutive numbers with n>1. 1
1, 5, 8, 16, 20, 21, 33, 36, 40, 56, 65, 85, 96, 120, 133, 161, 176, 180, 208, 224, 225, 261, 280, 320, 341, 385, 408, 432, 456, 481, 533, 560, 616, 645, 705, 736, 756, 800, 833, 901, 936, 1008, 1045, 1120, 1121, 1152, 1160, 1232, 1240 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..49.

FORMULA

Number = Product_{i=a..a+n-1} i / Sum_{i=a..a+n-1} i with a, n > 1

Integer values of (n+1)*binomial(a+n,a-1)/Sum_{i=0..n-1}(a+i) with a, n > 1

EXAMPLE

224 = 4*5*6*7*8/(4+5+6+7+8)

225 = 25*26*27/(25+26+27)

5544 = 11*12*13*14*15/(11+12+13+14+15)

CROSSREFS

Sequence in context: A314563 A314564 A314565 * A001082 A242090 A030006

Adjacent sequences:  A126692 A126693 A126694 * A126696 A126697 A126698

KEYWORD

easy,nonn

AUTHOR

Paolo P. Lava and Giorgio Balzarotti, Feb 15 2007, corrected Feb 20 2007 and Mar 06 2007

STATUS

approved

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Last modified March 30 12:10 EDT 2020. Contains 333125 sequences. (Running on oeis4.)