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A077656 Numbers having a different number of prime factors as their successors (counted with multiplicity). 2
1, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20, 22, 23, 24, 26, 28, 29, 30, 31, 32, 35, 36, 37, 39, 40, 41, 42, 43, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 76, 77, 78, 79, 80, 81, 82, 83 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A077655(a(n))=0; A001222(a(n))<>A001222(a(n)+1).

LINKS

Table of n, a(n) for n=1..71.

EXAMPLE

20=2*2*5 and 20+1=21=3*7: A001222(20)<>A001222(21), therefore 20 is a term (A077655(20)=0).

MATHEMATICA

Position[Partition[PrimeOmega[Range[100]], 2, 1], _?(#[[1]]!=#[[2]]&), {1}, Heads->False]//Flatten (* Harvey P. Dale, Sep 19 2016 *)

CROSSREFS

Cf. A001222, A045920.

Sequence in context: A047310 A184530 A304804 * A039236 A304808 A039180

Adjacent sequences:  A077653 A077654 A077655 * A077657 A077658 A077659

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Nov 13 2002

STATUS

approved

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Last modified June 16 14:16 EDT 2021. Contains 345057 sequences. (Running on oeis4.)