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A107800 a(n) = number of distinct primes dividing A006049(n) (and dividing (A006049(n)+1). 2
1, 1, 1, 1, 1, 2, 1, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

COMMENTS

a(n) first equals 3 when n is such that A006049(n) = 230.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..2500 from T. D. Noe)

FORMULA

a(n) = A001221(A006049(n)).

MATHEMATICA

f[n_] := Length@FactorInteger[n]; t = f /@ Range[300]; f /@ Flatten@Position[Rest[t] - Most[t], 0] (* Ray Chandler, Mar 27 2007 *)

CROSSREFS

Cf. A001221, A006049, A052215.

Sequence in context: A058978 A264998 A118916 * A245760 A085761 A102382

Adjacent sequences:  A107797 A107798 A107799 * A107801 A107802 A107803

KEYWORD

nonn

AUTHOR

Leroy Quet, Mar 24 2007

EXTENSIONS

Extended by Ray Chandler, Mar 27 2007

STATUS

approved

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Last modified August 6 15:42 EDT 2020. Contains 336253 sequences. (Running on oeis4.)