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A057922
d(n) divides d(n+1), where d(n) is number of positive divisors of n.
6
1, 2, 5, 7, 11, 13, 14, 17, 19, 21, 23, 26, 29, 31, 33, 34, 37, 38, 39, 41, 43, 44, 47, 49, 53, 55, 57, 59, 61, 65, 67, 69, 71, 73, 75, 77, 79, 83, 85, 86, 87, 89, 93, 94, 95, 97, 98, 101, 103, 104, 107, 109, 113, 116, 118, 119, 122, 125, 127, 129, 131, 133, 134, 135
OFFSET
0,2
LINKS
EXAMPLE
11 is included because d(11) = 2 divides d(12) = 6.
MATHEMATICA
Select[Range@150, Divisible @@ DivisorSigma[0, {# + 1, #}] &] (* Ivan Neretin, May 29 2015 *)
Position[Partition[DivisorSigma[0, Range[150]], 2, 1], _?(Divisible[#[[2]], #[[1]]]&), 1, Heads->False]//Flatten (* Harvey P. Dale, May 08 2019 *)
CROSSREFS
Sequence in context: A355774 A079933 A075610 * A243047 A113543 A189468
KEYWORD
nonn
AUTHOR
Leroy Quet, Nov 11 2000
STATUS
approved