|
Search: id:A126592
|
|
|
| A126592 |
|
Sum of numbers <=n which are multiples of 3 or 5. |
|
+0
3
|
|
| 0, 0, 3, 3, 8, 14, 14, 14, 23, 33, 33, 45, 45, 45, 60, 60, 60, 78, 78, 98, 119, 119, 119, 143, 168, 168, 195, 195, 195, 225, 225, 225, 258, 258, 293, 329, 329, 329, 368, 408, 408, 450, 450, 450, 495, 495, 495, 543, 543, 593, 644, 644, 644, 698, 753, 753, 810, 810
(list; graph; listen)
|
|
|
OFFSET
|
1,3
|
|
|
COMMENT
|
Sum of numbers m<=n such that mod(m,3)*mod(m,5)=0. See Problem 1 in Project Euler.
|
|
LINKS
|
C. Hughes, Project Euler.
|
|
FORMULA
|
an[n,d]=d*Floor[n/d];sn[n,d]=(an[n,d]*(an[n,d] + d))/(2*d); a(n)=sn[n,3]+sn[n,5]-sn[n,15].
|
|
MATHEMATICA
|
an[n_, d_]:=d*Floor[n/d]; sn[n_, d_]:=(an[n, d]*(an[n, d] + d))/(2*d); Table[sn[n, 3]+sn[n, 5]-sn[n, 15], {n, 1000}]
|
|
CROSSREFS
|
Cf. A126073, A126590.
Sequence in context: A105039 A090597 A126073 this_sequence A055057 A154029 A104864
Adjacent sequences: A126589 A126590 A126591 this_sequence A126593 A126594 A126595
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Zak Seidov (zakseidov(AT)gmail.com), Mar 13 2007
|
|
|
Search completed in 0.002 seconds
|
