|
|
A253177
|
|
Numbers which can be expressed with fewer 1s using +, -, and * than with + and *.
|
|
3
|
|
|
23, 47, 53, 59, 69, 71, 89, 94, 106, 107, 134, 141, 142, 143, 159, 161, 167, 177, 178, 179, 188, 191, 207, 212, 213, 214, 215, 227, 233, 239, 242, 251, 263, 265, 267, 268, 269, 282, 283, 284, 286, 287, 299, 311, 317, 318, 319, 321
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
Numbers n such that A005245(n) > A091333(n). Is it true that a(n) ~ n?
|
|
LINKS
|
|
|
EXAMPLE
|
23 = 2*3*4 - 1 = 3*(2*3 + 1) + 2 can be written with 10 1s using subtraction but requires 11 without, hence 23 is a member. Here the digits 2, 3, and 4 are used for clarity, but could be expanded to (1+1), (1+1+1), etc.
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|