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A054004
Numbers k such that k and k+1 have the same number and sum of divisors.
15
14, 1334, 1634, 2685, 33998, 42818, 64665, 84134, 109214, 122073, 166934, 289454, 383594, 440013, 544334, 605985, 649154, 655005, 792855, 1642154, 2284814, 2305557, 2913105, 3571905, 3682622, 4701537, 5181045, 6431732
OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..1831 (calculated using the b-file at A002961; terms 1..967 from T. D. Noe)
EXAMPLE
Divisors of 14 = {1, 2, 7, 14}, divisors of 15 = {1, 3, 5, 15}, both have four divisors and sum = 24.
MATHEMATICA
Select[Range[100000], DivisorSigma[0, #] == DivisorSigma[0, # + 1] && DivisorSigma[1, #] == DivisorSigma[1, # + 1] &] (* Jayanta Basu, Mar 20 2013 *)
KEYWORD
nonn
AUTHOR
Asher Auel, Jan 12 2000
EXTENSIONS
More terms from Jud McCranie, Jun 02 2000
STATUS
approved