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A054005
Sum of divisors of k such that k and k+1 have the same number and sum of divisors.
4
24, 2160, 2640, 4320, 51840, 65280, 115200, 138240, 194400, 186048, 276480, 483840, 622080, 700416, 950400, 984960, 1118880, 1128960, 1612800, 2661120, 3937248, 3617280, 5019840, 6128640, 5806080, 7375680, 8467200, 11583936
OFFSET
1,1
LINKS
FORMULA
a(n) = sigma(A054004(n)).
EXAMPLE
See example in A054004.
MATHEMATICA
Select[Partition[Table[{n, DivisorSigma[0, n], DivisorSigma[1, n]}, {n, 116*10^5}], 2, 1], #[[1, 2]]== #[[2, 2]] && #[[1, 3]]==#[[2, 3]]&][[All, 1, 3]] (* Harvey P. Dale, May 16 2023 *)
KEYWORD
nonn
AUTHOR
Asher Auel, Jan 12 2000
EXTENSIONS
More terms from Jud McCranie, Oct 15 2000
Definition clarified by Harvey P. Dale, May 16 2023
STATUS
approved