OFFSET
1,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Eric Weisstein's World of Mathematics, Magic Constant.
Index entries for linear recurrences with constant coefficients, signature (8,-28,56,-70,56,-28,8,-1).
FORMULA
a(n) = n^3/4 * (n^2 + 1)^2.
G.f.: x*(1 +42*x +303*x^2 +568*x^3 +303*x^4 +42*x^5 +x^6)/(1-x)^8 .
a(1)=1, a(2)=50, a(3)=675, a(4)=4624, a(5)=21125, a(6)=73926, a(7)= 214375, a(8)=540800, a(n) = 8*a(n-1) -28*a(n-2) +56*a(n-3) -70*a(n-4) + 56*a(n-5) -28*a(n-6) +8*a(n-7) -a(n-8). - Harvey P. Dale, Aug 14 2013
E.g.f.: x*(4 +96*x +352*x^2 +370*x^3 +142*x^4 +21*x^5 + x^6)*exp(x)/4. - G. C. Greubel, Sep 23 2019
MAPLE
seq(n^3*(1+n^2)^2/4, n=1..30); # G. C. Greubel, Sep 23 2019
MATHEMATICA
Table[n^3/4 (n^2+1)^2, {n, 30}] (* or *) LinearRecurrence[{8, -28, 56, -70, 56, -28, 8, -1}, {1, 50, 675, 4624, 21125, 73926, 214375, 540800}, 30] (* Harvey P. Dale, Aug 14 2013 *)
CoefficientList[Series[(1+42x+303x^2+568x^3+303x^4+42x^5+x^6)/(1-x)^8, {x, 0, 40}], x] (* Vincenzo Librandi, Aug 14 2013 *)
PROG
(PARI) vector(30, n, n^3*(1+n^2)^2/4) \\ G. C. Greubel, Sep 23 2019
(Magma) [n^3*(1+n^2)^2/4: n in [1..30]]; // G. C. Greubel, Sep 23 2019
(Sage) [n^3*(1+n^2)^2/4 for n in (1..30)] # G. C. Greubel, Sep 23 2019
(GAP) List([1..30], n-> n^3*(1+n^2)^2/4); # G. C. Greubel, Sep 23 2019
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved