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A003503 The larger of a betrothed pair. 6
75, 195, 1925, 1648, 2295, 6128, 16587, 20735, 75495, 206504, 219975, 309135, 507759, 549219, 544784, 817479, 1057595, 1902215, 1331967, 1159095, 1763019, 1341495, 1348935, 1524831, 1459143, 2576945, 2226014, 2681019, 2142945, 2421704, 3220119, 3123735 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

It has been shown that (1) all known betrothed pairs are of opposite parity and (2) if a and b are a betrothed pair, and if a < b are of the same parity, then a > 10^10. See the reference for the Hagis & Lord paper. Can it be shown that all betrothed pairs are of opposite parity? - Harvey P. Dale, Apr 07 2013

REFERENCES

R. K. Guy, Unsolved Problems in Number Theory, B5.

LINKS

Donovan Johnson, Table of n, a(n) for n = 1..1000

P. Hagis and G. Lord, Quasi-amicable numbers, Math. Comp. 31 (1977), 608-611.

CROSSREFS

Cf. A003502,  A005276.

Sequence in context: A228306 A044407 A044788 * A201916 A098230 A258056

Adjacent sequences:  A003500 A003501 A003502 * A003504 A003505 A003506

KEYWORD

nonn,nice

AUTHOR

Robert G. Wilson v

EXTENSIONS

Computed by Fred W. Helenius (fredh(AT)ix.netcom.com)

Extended by T. D. Noe, Dec 29 2011

STATUS

approved

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Last modified November 23 00:33 EST 2017. Contains 295107 sequences.