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Search: id:A045945
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| A045945 |
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Hexagonal matchstick numbers: 3n(3n+1). |
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+0
3
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| 0, 12, 42, 90, 156, 240, 342, 462, 600, 756, 930, 1122, 1332, 1560, 1806, 2070, 2352, 2652, 2970, 3306, 3660, 4032, 4422, 4830, 5256, 5700, 6162, 6642, 7140, 7656, 8190, 8742, 9312, 9900, 10506, 11130, 11772, 12432, 13110, 13806, 14520, 15252, 16002
(list; graph; listen)
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OFFSET
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0,2
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FORMULA
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a(n)=18*n+a(n-1)-24 (with a(1)=0) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Nov 13 2009]
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EXAMPLE
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For n=2, a(2)=18*2+0-24=12; n=3, a(3)=18*3+12-24=42; n=4, a(4)=18*4+42-24=90 [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Nov 13 2009]
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MAPLE
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a:=n->sum(n+1, j=1..n): seq(a(n*3), n=0..42); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 03 2007
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CROSSREFS
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Cf. A033580, A045946.
Sequence in context: A022672 A109275 A085798 this_sequence A005901 A090554 A009948
Adjacent sequences: A045942 A045943 A045944 this_sequence A045946 A045947 A045948
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KEYWORD
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nonn,new
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AUTHOR
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R. K. Guy
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