|
Search: id:A140154
|
|
|
| A140154 |
|
a(1)=1, a(n)=a(n-1)+n^3 if n odd, a(n)=a(n-1)+ n^2 if n is even. |
|
+0
2
|
|
| 1, 5, 32, 48, 173, 209, 552, 616, 1345, 1445, 2776, 2920, 5117, 5313, 8688, 8944, 13857, 14181, 21040, 21440, 30701, 31185, 43352, 43928, 59553, 60229, 79912, 80696, 105085, 105985, 135776, 136800, 172737, 173893, 216768, 218064, 268717
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
FORMULA
|
a(n)=a(n-1)+{[1-(-1)^n]/2}*n^3+{[1+(-1)^n]/2}*n^2, with a(1)=1 a(n)= (-1/16)+(1/4)*(-1)^n*n+(1/16)*(-1)^n-(1/4)*(-1)^n*n^3+(5/12)*n^3-(1/8)*(-1)^n*n^2+(3/8)*n^2+(1 /12)*n+(1/8)*n^4 , with n>=1 - Paolo P. Lava (ppl(AT)spl.at), Jun 06 2008
|
|
MATHEMATICA
|
a = {}; r = 3; s = 2; Do[k = 0; Do[k = k + (Sin[Pi m/2]^2) m^r + (Cos[Pi m/2]^2) m^s, {m, 1, n}]; AppendTo[a, k], {n, 1, 100}]; a (*Artur Jasinski*)
|
|
CROSSREFS
|
Cf. A000027, A000217, A000330, A000537, A000538, A000539, A136047, A140113.
Adjacent sequences: A140151 A140152 A140153 this_sequence A140155 A140156 A140157
Sequence in context: A088548 A062631 A100840 this_sequence A073694 A101966 A089574
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Jasinski Artur (grafix(AT)csl.pl), May 12 2008
|
|
|
Search completed in 0.002 seconds
|
