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A057921 d(n+1) divides d(n), where d(n) is number of positive divisors of n. 4
2, 6, 10, 12, 14, 18, 21, 22, 26, 28, 30, 33, 34, 38, 40, 42, 44, 46, 52, 54, 56, 57, 58, 60, 66, 70, 72, 75, 78, 80, 82, 84, 85, 86, 88, 90, 93, 94, 96, 98, 102, 104, 105, 106, 108, 110, 112, 114, 116, 118, 122, 126, 128, 130, 132, 133, 135, 136, 138, 140, 141, 142 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Ivan Neretin, Table of n, a(n) for n = 0..10000

EXAMPLE

10 is included because d(11) = 2 divides d(10) = 4.

MATHEMATICA

Select[Range@150, Divisible @@ DivisorSigma[0, {#, # + 1}] &] (* Ivan Neretin, May 29 2015 *)

CROSSREFS

Cf. A057922, A005237.

Sequence in context: A305634 A139710 A194712 * A095300 A097381 A264964

Adjacent sequences:  A057918 A057919 A057920 * A057922 A057923 A057924

KEYWORD

nonn

AUTHOR

Leroy Quet, Nov 11 2000

STATUS

approved

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Last modified October 21 08:16 EDT 2019. Contains 328292 sequences. (Running on oeis4.)