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A100150
Structured snub cubic numbers.
3
1, 24, 107, 288, 605, 1096, 1799, 2752, 3993, 5560, 7491, 9824, 12597, 15848, 19615, 23936, 28849, 34392, 40603, 47520, 55181, 63624, 72887, 83008, 94025, 105976, 118899, 132832, 147813, 163880, 181071, 199424, 218977, 239768, 261835, 285216, 309949, 336072
OFFSET
1,2
FORMULA
a(n) = (1/6)*(38*n^3 - 48*n^2 + 16*n).
G.f.: x*(1 + 20*x + 17*x^2)/(1-x)^4. - Colin Barker, Jan 19 2012
From Elmo R. Oliveira, Aug 05 2025: (Start)
E.g.f.: exp(x)*x*(19*x^2 + 33*x + 3)/3.
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n > 4. (End)
MATHEMATICA
LinearRecurrence[{4, -6, 4, -1}, {1, 24, 107, 288}, 40] (* Harvey P. Dale, Sep 17 2020 *)
PROG
(PARI) a(n)=n*(38*n^2-48*n+16)/6 \\ Charles R Greathouse IV, Jul 18 2011
(Magma) [(1/6)*(38*n^3-48*n^2+16*n): n in [1..40]]; // Vincenzo Librandi, Jul 19 2011
CROSSREFS
Cf. A100149, A100151 for adjacent structured Archimedean solids; and A100145 for more on structured polyhedral numbers.
Sequence in context: A213874 A100149 A013980 * A305950 A060334 A271915
KEYWORD
nonn,easy
AUTHOR
James A. Record (james.record(AT)gmail.com), Nov 07 2004
EXTENSIONS
Deleted extra +16 in formula, corrected by Craig Ferguson, Jul 18 2011
STATUS
approved