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A100187 Structured octagonal anti-diamond numbers (vertex structure 7). 3
1, 18, 77, 204, 425, 766, 1253, 1912, 2769, 3850, 5181, 6788, 8697, 10934, 13525, 16496, 19873, 23682, 27949, 32700, 37961, 43758, 50117, 57064, 64625, 72826, 81693, 91252, 101529, 112550, 124341, 136928 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = (1/6)*(26*n^3-30*n^2+10*n).

G.f.: x*(1+14*x+11*x^2)/(1-x)^4. - Colin Barker, Jan 19 2012

PROG

(MAGMA) [(1/6)*(26*n^3-30*n^2+10*n): n in [1..40]]; // Vincenzo Librandi, Aug 18 2011

CROSSREFS

Cf. A063523 = alternate vertex; A100188 = structured anti-diamonds; A100145 for more on structured numbers.

Sequence in context: A143666 A139757 A164603 * A197886 A039453 A063495

Adjacent sequences:  A100184 A100185 A100186 * A100188 A100189 A100190

KEYWORD

nonn,easy

AUTHOR

James A. Record (james.record(AT)gmail.com), Nov 07 2004

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Last modified February 17 03:45 EST 2012. Contains 205978 sequences.