cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A120033 Number of semiprimes s such that 2^n < s <= 2^(n+1).

Table of values

n a(n)
0 0
1 1
2 1
3 4
4 4
5 12
6 20
7 40
8 75
9 147
10 285
11 535
12 1062
13 2006
14 3918
15 7548
16 14595
17 28293
18 54761
19 106452
20 206421
21 401522
22 780966
23 1520543
24 2962226
25 5777162
26 11272279
27 22009839
28 43006972
29 84077384
30 164482781
31 321944211
32 630487562
33 1235382703

List of values

[0, 1, 1, 4, 4, 12, 20, 40, 75, 147, 285, 535, 1062, 2006, 3918, 7548, 14595, 28293, 54761, 106452, 206421, 401522, 780966, 1520543, 2962226, 5777162, 11272279, 22009839, 43006972, 84077384, 164482781, 321944211, 630487562, 1235382703]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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