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.

A343521 a(n) = Sum_{1 <= x_1 <= x_2 <= x_3 <= x_4 <= x_5 <= x_6 <= x_7 <= n} gcd(x_1, x_2, x_3 , x_4, x_5, x_6, x_7, n).

Table of values

n a(n)
1 1
2 9
3 38
4 130
5 334
6 846
7 1722
8 3572
9 6513
10 11806
11 19458
12 32948
13 50400
14 79290
15 117092
16 174256
17 245173
18 354249
19 480718
20 670420
21 891690
22 1203578
23 1560802
24 2076496
25 2630915
26 3416352
27 4285152
28 5461348
29 6724548
30 8490884
31 10295502
32 12798224
33 15420213
34 18888861

List of values

[1, 9, 38, 130, 334, 846, 1722, 3572, 6513, 11806, 19458, 32948, 50400, 79290, 117092, 174256, 245173, 354249, 480718, 670420, 891690, 1203578, 1560802, 2076496, 2630915, 3416352, 4285152, 5461348, 6724548, 8490884, 10295502, 12798224, 15420213, 18888861]

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

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