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A212610 Pairs of primitive deficient numbers having the same value of sigma(k)/k, listed by increasing value of the larger of the two k values. 5
135, 819, 3375, 6975, 25137, 40131, 68607, 154791, 22113, 448335, 557375, 721525, 451737, 1401543, 1278316, 1680705, 273, 2876211, 6739509, 10590125, 188325, 11208375, 8775, 12525435, 9020375, 13934375, 20365625, 56162575, 1083537, 83479977, 3416875 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

"Primitive" means that the pair (a(2n-1),a(n)) = (k,k') is not a multiple of another such pair occurring earlier. - M. F. Hasler, Feb 25 2013

LINKS

Donovan Johnson, Table of n, a(n) for n = 1..48

FORMULA

a(2n-1) = A212611(n), a(2n) = A212612(n), for all n>0. - M. F. Hasler, Feb 22 2013

CROSSREFS

Cf. A211680 (non-primitive pairs), A212611, A212612 (the pairs separated).

Sequence in context: A328651 A159201 A211680 * A336554 A238330 A157734

Adjacent sequences:  A212607 A212608 A212609 * A212611 A212612 A212613

KEYWORD

nonn

AUTHOR

T. D. Noe, May 23 2012

EXTENSIONS

a(19)-a(31) from Donovan Johnson, May 24 2012

STATUS

approved

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Last modified July 3 16:27 EDT 2022. Contains 355055 sequences. (Running on oeis4.)