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A055831
T(n,n-4), where T is the array in A055830.
4
5, 15, 31, 54, 85, 125, 175, 236, 309, 395, 495, 610, 741, 889, 1055, 1240, 1445, 1671, 1919, 2190, 2485, 2805, 3151, 3524, 3925, 4355, 4815, 5306, 5829, 6385, 6975, 7600, 8261, 8959, 9695, 10470, 11285, 12141, 13039
OFFSET
4,1
FORMULA
a(n) = (n-3)*(n^2+6*n-10)/6, n>3.
G.f.: x^4*(5-5*x+x^2)/(1-x)^4. - R. J. Mathar, Mar 13 2016
E.g.f.: (-30 - 6*x + 3*x^2 + (30 - 24*x + 6*x^2 + x^3)*exp(x))/6. - G. C. Greubel, Jan 21 2020
MAPLE
seq( (n-3)*(n^2+6*n-10)/6, n=4..40); # G. C. Greubel, Jan 21 2020
MATHEMATICA
Table[(n-3)*(n^2+6*n-10)/6, {n, 4, 40}] (* G. C. Greubel, Jan 21 2020 *)
PROG
(PARI) a(n) = (n-3)*(n^2+6*n-10)/6; \\ G. C. Greubel, Jan 21 2020
(Magma) [(n-3)*(n^2+6*n-10)/6: n in [4..40]]; // G. C. Greubel, Jan 21 2020
(Sage) [(n-3)*(n^2+6*n-10)/6 for n in (4..40)] # G. C. Greubel, Jan 21 2020
(GAP) List([4..40], n-> (n-3)*(n^2+6*n-10)/6); # G. C. Greubel, Jan 21 2020
CROSSREFS
Cf. A055830.
Sequence in context: A225325 A133268 A056108 * A346823 A037984 A298032
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, May 28 2000
STATUS
approved