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Search: id:A131998
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| A131998 |
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Numbers n such that the number of letters in the n-th ordinal number divides n. |
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+0
1
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| 5, 7, 10, 24, 33, 40, 44, 70, 78, 84, 90, 99, 105, 126, 132, 168, 176, 189, 190, 198, 208, 210, 231, 252, 306, 315, 340, 360, 368, 384, 391, 408, 420, 441, 462, 480, 520, 546, 575, 580, 598, 600, 608, 612, 638, 682, 693, 700, 702, 736, 740, 760, 770, 792, 814
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Which numbers k occur as the dividends?
k...smallest n such that A006944(n)/n = k.
1...5.
2..10.
3..11
4..44.
5..never?
6..78.
7..70.
8.168.
9.189.
10.90.
11.99.
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FORMULA
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{n such that A006944(n)|n}.
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EXAMPLE
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a(1) = 5 because "fifth" has 5 letters.
a(2) = 7 because "seventh" has 7 letters.
a(3) = 10 because "tenth" has 5 letters, and 10/5 = 2.
a(4) = 24 because "twentyfourth" has 12 letters, and 24/12 = 2.
a(5) = 33 because "thirtythird" has 11 letters, and 33/11 = 3.
a(6) = 44 because "fortyfourth" has 11 letters, and 44/11 = 4.
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CROSSREFS
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Cf. A006944, A116910.
Sequence in context: A073895 A113194 A088768 this_sequence A141443 A015849 A059303
Adjacent sequences: A131995 A131996 A131997 this_sequence A131999 A132000 A132001
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KEYWORD
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easy,nonn,word
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AUTHOR
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Jonathan Vos Post (jvospost3(AT)gmail.com), Oct 08 2007
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EXTENSIONS
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Corrected and extended by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 24 2007
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