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A007594 Smallest n-hyperperfect number: m such that m=n(sigma(m)-m-1)+1; or 0 if no such number exists.
(Formerly M4150)
0
6, 21, 325, 1950625 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Jud McCranie reports that the following terms are known:
6,21,325,1950625,?,301,?,?,?,159841,10693,697,?,?,?,
69091933912976476978420033,?,1333,51301,?,?,
865004941741938633917612789573739286076451841,?,?,?,?,?
where the missing terms, if they exist, are > 10^11. The large terms for 16 and 22 are the smallest known (7/98).
REFERENCES
J. Roberts, Lure of the Integers, Math. Assoc. America, 1992, p. 177.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
J. S. McCranie, A study of hyperperfect numbers, J. Int. Seqs. Vol. 3 (2000) #P00.1.3.
Daniel Minoli, Issues In Non-Linear Hyperperfect Numbers, Mathematics of Computation, Vol. 34, No. 150, April 1980, pp. 639-645.
CROSSREFS
Sequence in context: A164643 A190275 A261844 * A316775 A181593 A084539
KEYWORD
nonn
AUTHOR
STATUS
approved

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Last modified March 2 21:56 EST 2024. Contains 370498 sequences. (Running on oeis4.)