A063523 a(n) = n*(8*n^2 - 5)/3.

0, 1, 18, 67, 164, 325, 566, 903, 1352, 1929, 2650, 3531, 4588, 5837, 7294, 8975, 10896, 13073, 15522, 18259, 21300, 24661, 28358, 32407, 36824, 41625, 46826, 52443, 58492, 64989, 71950, 79391, 87328, 95777, 104754, 114275, 124356

Offset

0,3

Comments

Also as a(n)=(1/6)*(16*n^3-10*n), n>0: structured octagonal anti-diamond numbers (vertex structure 17) (Cf. A100187 = alternate vertex; A100188 = structured anti-diamonds; A100145 for more on structured numbers). - James A. Record (james.record(AT)gmail.com), Nov 07 2004

Links

Harry J. Smith, Table of n, a(n) for n = 0..1000

T. P. Martin, Shells of atoms, Phys. Reports, 273 (1996), 199-241, eq. (11).

Index entries for linear recurrences with constant coefficients, signature (4, -6, 4, -1).

Formula

a(0)=0, a(1)=1, a(2)=18, a(3)=67, a(n)=4*a(n-1)-6*a(n-2)+4*a(n-3)- a(n-4). - Harvey P. Dale, Jul 11 2011

G.f.: (x+14*x^2+x^3)/(x-1)^4. - Harvey P. Dale, Jul 11 2011

E.g.f.: (x/3)*(3 + 24*x + 8*x^2)*exp(x). - G. C. Greubel, Sep 01 2017

Mathematica

Table[n(8n^2-5)/3, {n, 0, 80}] (* Vladimir Joseph Stephan Orlovsky, Apr 18 2011 *)
LinearRecurrence[{4, -6, 4, -1}, {0, 1, 18, 67}, 81] (* or *) CoefficientList[ Series[ (x+14 x^2+x^3)/(x-1)^4, {x, 0, 80}], x] (* Harvey P. Dale, Jul 11 2011 *)

Prog

(PARI) for (n=0, 1000, write("b063523.txt", n, " ", n*(8*n^2 - 5)/3) ) \\ Harry J. Smith, Aug 25 2009

Crossrefs

1/12*t*(n^3-n)+n for t = 2, 4, 6, ... gives A004006, A006527, A006003, A005900, A004068, A000578, A004126, A000447, A004188, A004466, A004467, A007588, A062025, A063521, A063522, A063523.

Sequence in context: A044156 A044537 A143859 * A045234 A158056 A304061

Adjacent sequences: A063520 A063521 A063522 * A063524 A063525 A063526

Keyword

nonn,easy

Author

N. J. A. Sloane, Aug 02 2001

Status

approved