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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.

A247087 a(n) = pi(phi(p(P(n)))) = A000720(A000010(A000041(A000040(n)))).

Table of values

n a(n)
1 0
2 1
3 3
4 4
5 9
6 25
7 41
8 39
9 168
10 462
11 442
12 1939
13 2571
14 3998
15 5123
16 17040
17 24853
18 38887
19 195022
20 183430
21 404386
22 381060
23 1162366
24 2105509
25 1799881
26 5966593
27 5380661
28 14184985
29 10473967
30 22631261
31 135452589
32 109540327
33 244730051
34 487610708
35 604467085
36 671043205
37 3350187738

List of values

[0, 1, 3, 4, 9, 25, 41, 39, 168, 462, 442, 1939, 2571, 3998, 5123, 17040, 24853, 38887, 195022, 183430, 404386, 381060, 1162366, 2105509, 1799881, 5966593, 5380661, 14184985, 10473967, 22631261, 135452589, 109540327, 244730051, 487610708, 604467085, 671043205, 3350187738]

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

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