A349838 -id:A349838 - cp's OEIS frontend

A349917 a(n) is the unique k such that A349838(n) = A051281(k).

1, 2, 3, 6, 8, 4, 7, 11, 9, 14, 30, 5, 19, 29, 12, 22, 23, 33, 44, 15, 27, 28, 50, 17, 18, 45, 46, 53, 20, 21, 35, 47, 48, 24, 25, 37, 51, 63, 64, 91, 10, 26, 41, 42, 43, 57, 58, 71, 85, 59, 60, 61, 78, 79, 31, 65, 66, 82, 83, 100, 34, 69, 13, 36, 55, 56, 74

Offset: 1

Rémy Sigrist, Dec 05 2021

This sequence is a permutation of the natural numbers.

			For n = 8:
- A349838(8) = 27559 = A051281(11),
- so a(8) = 11.

Rémy Sigrist, Table of n, a(n) for n = 1..3309
Rémy Sigrist, PARI program for A349917
Index entries for sequences that are permutations of the natural numbers

Cf. A051281, A349838.

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A349837 a(n) is the number of integers m > 1 such that sigma(m) = tau(m)^n, with a(1) = 1.

Original entry on oeis.org

1, 1, 1, 2, 3, 3, 3, 5, 4, 5, 5, 7, 9, 5, 6, 2, 7, 7, 5, 6, 5, 9, 6, 11, 6, 12, 10, 12, 14, 11, 13, 21, 16, 20, 19, 20, 19, 21, 21, 19, 17, 21, 18, 22, 19, 22, 20, 17, 17, 15, 23, 14, 17, 12, 16, 9, 11, 12, 10, 9, 9, 7, 10, 3, 8, 7, 6, 3, 7, 4, 4, 4, 3, 3, 2

Offset: 1

Rémy Sigrist, Dec 01 2021

nonn

a(n) is the number of integers m such that A334455(m) = n.

Conjecture: a(n) > 0 except for n = 76 and n = 81.

Rémy Sigrist, Table of n, a(n) for n = 1..5000
Rémy Sigrist, PARI program for A349837

Cf. A000005 (tau), A000203 (sigma), A334455, A349006, A349007, A349838.

PARI
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cp's OEIS Frontend

A349917 a(n) is the unique k such that A349838(n) = A051281(k).

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