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A102299 Number of prime divisors with multiplicity of n where n and n+1 are composite or twin composite numbers. 0
3, 2, 2, 2, 3, 2, 4, 2, 2, 3, 5, 2, 2, 2, 2, 2, 3, 3, 5, 2, 3, 2, 4, 2, 4, 2, 2, 3, 6, 2, 3, 2, 2, 3, 3, 2, 5, 4, 4, 2, 2, 2, 4, 2, 3, 2, 2, 2, 3, 3, 4, 3, 3, 2, 3, 2, 3, 3, 2, 2, 5, 2, 2, 2, 3, 3, 7, 2, 4, 2, 2, 4, 4, 2, 2, 2, 6, 2, 2, 3, 4, 3, 3, 2, 2, 2, 6, 2, 3, 3, 5, 2, 3, 3, 3, 3, 5, 2, 3, 2, 4, 2, 3, 2, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..105.

EXAMPLE

For n=8 n+1=9 a twin composite pair. 8=2*2*2 or product of 3 prime divisors with multiplicity.

MATHEMATICA

Total[Transpose[FactorInteger[#]][[2]]]&/@Transpose[Select[Partition[Complement[Range[250], Prime[Range[PrimePi[250]]]], 2, 1], #[[2]]-#[[1]]==1&]][[1]] (* Harvey P. Dale, Nov 25 2010 *)

PROG

(PARI) f1(n) = for(x=1, n, y=composite(x); if(!isprime(y+1), print1(bigomega(y)", "))) composite(n) =\The n-th composite number. 1 is def as not prime nor composite. { local(c, x); c=1; x=1; while(c <= n, x++; if(!isprime(x), c++); ); return(x) }

CROSSREFS

Sequence in context: A207384 A085034 A119323 * A302481 A306542 A335171

Adjacent sequences:  A102296 A102297 A102298 * A102300 A102301 A102302

KEYWORD

easy,nonn

AUTHOR

Cino Hilliard, Feb 19 2005

STATUS

approved

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Last modified May 16 02:09 EDT 2022. Contains 353687 sequences. (Running on oeis4.)