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A344314
Number k such that k and k+1 have the same number of nonunitary divisors (A048105).
7
1, 2, 5, 6, 10, 13, 14, 21, 22, 27, 29, 30, 33, 34, 37, 38, 41, 42, 44, 46, 57, 58, 61, 65, 66, 69, 70, 73, 75, 77, 78, 82, 85, 86, 93, 94, 98, 101, 102, 105, 106, 109, 110, 113, 114, 116, 118, 122, 124, 129, 130, 133, 135, 137, 138, 141, 142, 145, 147, 154, 157
OFFSET
1,2
LINKS
EXAMPLE
1 is a term since A048105(1) = A048105(2) = 0.
27 is a term since A048105(27) = A048105(28) = 2.
MATHEMATICA
nd[n_] := DivisorSigma[0, n] - 2^PrimeNu[n]; Select[Range[200], nd[#] == nd[# + 1] &]
CROSSREFS
Similar sequences: A005237, A006049, A343819, A344312, A344313.
Sequence in context: A089269 A047440 A255055 * A369020 A358817 A369166
KEYWORD
nonn
AUTHOR
Amiram Eldar, May 14 2021
STATUS
approved