OFFSET
1,1
LINKS
Colin Barker (Corrected by Harvey P. Dale), Table of n, a(n) for n = 1..1000
Hamzeh Mujahed, Benedek Nagy, Hyper-Wiener Index on Rows of Unit Cells of the BCC Grid, Comptes rendus de l’Académie bulgare des Sciences, Tome 71, No 5, 2018, 675-684.
Index entries for linear recurrences with constant coefficients, signature (5,-10,10,-5,1).
FORMULA
a(n) = (25*n^4 + 105*n^3 + 143*n^2 + 171*n + 108)/6 (proven).
From Colin Barker, Jun 11 2018: (Start)
G.f.: x*(92 - 83*x + 163*x^2 - 90*x^3 + 18*x^4 + 50*x^5 - 250*x^6 + 500*x^7 - 500*x^8 + 250*x^9 - 50*x^10) / (1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5) for n>11.
(End)
MATHEMATICA
Table[(25n^4+105n^3+143n^2+171n+108)/6, {n, 40}] (* or *) LinearRecurrence[ {5, -10, 10, -5, 1}, {92, 377, 1128, 2700, 5548}, 40] (* Harvey P. Dale, Sep 19 2020 *)
PROG
(PARI) Vec(x*(92 - 83*x + 163*x^2 - 90*x^3 + 18*x^4 + 50*x^5 - 250*x^6 + 500*x^7 - 500*x^8 + 250*x^9 - 50*x^10) / (1 - x)^5 + O(x^40)) \\ Colin Barker, Jun 11 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Benedek Nagy, Jun 09 2018
EXTENSIONS
Corrected and extended by Harvey P. Dale, Sep 19 2020
STATUS
approved