|
| |
|
|
A064394
|
|
Exponent of highest power of 2 dividing n! equals the largest prime < n.
|
|
2
| |
|
|
4, 5, 8, 9, 22, 23, 26, 27, 32, 33, 50, 51, 56, 57, 70, 71, 76, 77, 82, 83, 94, 95, 100, 101, 112, 113, 118, 119, 128, 129, 134, 135, 176, 177, 186, 187, 196, 197, 266, 267, 274, 275, 280, 281, 296, 297, 342, 343, 352, 353, 358, 359, 364, 365, 372, 373, 386, 387
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,1
|
|
|
COMMENTS
| [n/2]+[n/4]+[n/8]+[n/16]+... = prevprime(n).
|
|
|
EXAMPLE
| 8!=2^7*3^2*5*7, 23!=2^19*3^9*5^4*7^3*11^2*13*17*19*23.
|
|
|
MAPLE
| for n from 3 to 10^3 do if sum(floor(n/(2^i)), i=1..15) = prevprime(n) then printf(`%d, `, n) fi; od:
|
|
|
CROSSREFS
| Cf. A011371, A007917.
Sequence in context: A020934 A094004 A067271 * A092022 A190200 A162902
Adjacent sequences: A064391 A064392 A064393 * A064395 A064396 A064397
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 29 2001
|
|
|
EXTENSIONS
| More terms from James A. Sellers (sellersj(AT)math.psu.edu), Oct 01 2001
|
| |
|
|
