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A100171
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Structured triakis octahedral numbers (vertex structure 4).
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2
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1, 14, 60, 160, 335, 606, 994, 1520, 2205, 3070, 4136, 5424, 6955, 8750, 10830, 13216, 15929, 18990, 22420, 26240, 30471, 35134, 40250, 45840, 51925, 58526, 65664, 73360, 81635, 90510, 100006, 110144
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 1..10000
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FORMULA
| a(n)=(1/6)*(21*n^3-27*n^2+12*n)
a(0)=1, a(1)=14, a(2)=60, a(3)=160, a(n)=4*a(n-1)-6*a(n-2)+4*a(n-3)-a(n-4) [From Harvey P. Dale, June 28 2011]
G.f.: (10*x^2+10*x+1)/(x-1)^4 [From Harvey P. Dale, June 28 2011]
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MATHEMATICA
| Table[(21n^3-27n^2+12n)/6, {n, 40}] (* or *) LinearRecurrence[ {4, -6, 4, -1}, {1, 14, 60, 160}, 40] (* From Harvey P. Dale, June 28 2011 *)
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PROG
| (MAGMA) [(1/6)*(21*n^3-27*n^2+12*n): n in [1..40]]; // Vincenzo Librandi, Jul 27 2011
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CROSSREFS
| Cf. A100157 = alternate vertex; A100145 for more on structured numbers.
Sequence in context: A120371 A062022 A158058 * A063492 A051799 A164540
Adjacent sequences: A100168 A100169 A100170 * A100172 A100173 A100174
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KEYWORD
| easy,nonn
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AUTHOR
| James A. Record (james.record(AT)gmail.com). Nov 07, 2004.
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