|
| |
|
|
A093153
|
|
Difference between counts of odd composites in A093151 and A093152 [Count (1 mod 4) - count (3 mod 4)].
|
|
3
| |
|
|
0, 1, 6, 9, 24, 146, 217, 445, 550, 5959, 14251, 63336, 118471, 183456, 951699, 3458333, 6284059, 2581690, 80743227, 259753424
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,3
|
|
|
COMMENTS
| In A091295 the counts are 1 higher. I computed the differences through 10^8 and the rest by extrapolating from A091098 and A091099. In the ranges given, the counts of odd composites less than 10^n are higher 1 mod 4 than 3 mod 4. They are exactly opposite for the primes less than 10^n where 3 mod 4 is higher.
|
|
|
FORMULA
| Subtract count of odd composites 3 mod 4 less than 10^n from those 1 mod 4
a(n) = A093151(n) - A093152(n). For n>1, a(n) = A091099(n) - A091098(n) - 1. [From Max Alekseyev (maxale(AT)gmail.com), May 17 2009]
|
|
|
EXAMPLE
| Below 10^3 there are 169 odd composites 1 mod 4 and 163 odd composites 3 mod 4, so a(3)=169-163=6
|
|
|
CROSSREFS
| Cf. A093151 A093152 A091295 A091098 A091099.
Sequence in context: A084431 A176498 A142877 * A115646 A115644 A024878
Adjacent sequences: A093150 A093151 A093152 * A093154 A093155 A093156
|
|
|
KEYWORD
| more,nonn
|
|
|
AUTHOR
| Enoch Haga (Enokh(AT)comcast.net), Mar 24 2004
|
|
|
EXTENSIONS
| More terms from Max Alekseyev (maxale(AT)gmail.com), May 17 2009
|
| |
|
|
