|
| |
|
|
A131536
|
|
Least power of 2 having exactly n consecutive 2's in its decimal representation.
|
|
0
| |
|
|
1, 51, 43, 692, 314, 2354, 8555, 13326, 81784, 279272, 865356, 1727608, 1727602
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
EXAMPLE
| a(3)=43 because 2^43(i.e. 8796093022208) is the smallest power of 2 to contain a run of 3 consecutive twos in its decimal form.
|
|
|
MATHEMATICA
| a = ""; Do[ a = StringJoin[a, "2"]; b = StringJoin[a, "2"]; k = 1; While[ StringPosition[ ToString[2^k], a] == {} || StringPosition[ ToString[2^k], b] != {}, k++ ]; Print[k], {n, 1, 10} ]
|
|
|
CROSSREFS
| Sequence in context: A160474 A033371 A191514 * A204375 A003912 A039932
Adjacent sequences: A131533 A131534 A131535 * A131537 A131538 A131539
|
|
|
KEYWORD
| more,nonn,base
|
|
|
AUTHOR
| Shyam Sunder Gupta (guptass(AT)rediffmail.com), Aug 26 2007
|
|
|
EXTENSIONS
| 3 more terms from Sean A. Irvine (sairvin(AT)xtra.co.nz), Jul 19 2010
|
| |
|
|
