A034898 - OEIS

A034898

n-th term of A034897 is an a(n)-hyperperfect number.

1, 2, 1, 6, 3, 1, 12, 18, 18, 12, 2, 30, 1, 11, 6, 2, 60, 48, 19, 132, 132, 10, 192, 2, 31, 168, 108, 66, 35, 252, 78, 132, 342, 366, 390, 168, 348, 282, 498, 540, 546, 59, 12, 378, 438, 4, 222, 336, 18, 660, 138, 798, 810, 528, 450, 75, 252, 150, 948, 162

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OFFSET

1,2

REFERENCES

R. K. Guy, Unsolved Problems in Number Theory, Sect. B2.

Roberts, Lure of the Integers, see Integer 28, p. 177.

LINKS

Donovan Johnson, Table of n, a(n) for n = 1..10000

Judson S. McCranie, A Study of Hyperperfect Numbers, Journal of Integer Sequences, Vol. 3 (2000), Article 00.1.3.

Eric Weisstein's World of Mathematics, Hyperperfect Number.

PROG

(PARI) forcomposite(n=2, 10^8, if(1==Mod(n, sigma(n)-n-1), print1((n-1)/(sigma(n)-n-1)", "))) \\ Hans Loeblich, May 10 2019