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A144586 a(n) = odd and nonprime sum of prime factors of composite(k)=A002808(k). 0
9, 9, 9, 15, 9, 21, 15, 25, 33, 21, 39, 45, 27, 49, 15, 55, 15, 33, 63, 35, 15, 15, 69, 75, 15, 25, 81, 15, 45, 85, 25, 91, 15, 51, 15, 99, 21, 105, 21, 57, 15, 111, 115, 21, 35, 21, 63, 15, 65, 129, 25, 35, 133, 25, 21, 141, 75, 27, 77, 153, 27, 25, 159, 165, 21, 87, 169, 27 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..68.

EXAMPLE

If A002808(7)=14=2*7 and 2+7=9(odd nonprime), then 9=a(1). If A002808(11)=20=2*2*5 and 2+2+5=9(odd nonprime), then 9=a(2). If A002808(14)=24=2*2*2*3 and 2+2+2+3=9(odd nonprime), then 9=a(3). If A002808(16)=26=2*13 and 2+13=15(odd nonprime), then 15=a(4), etc.

MAPLE

Contribution from R. J. Mathar, May 01 2010: (Start)

pss := proc(n) a := 0 ; for d in ifactors(n)[2] do a := a+ op(2, d)*op(1, d) ; end do: a ; end proc:

A002808 := proc(n) if n = 1 then 4; else for a from procname(n-1)+1 do if not isprime(a) then return a; end if; end do: end if; end proc:

A046343 := proc(n) pss(A002808(n)) ; end proc:

for k from 1 to 800 do a := A046343(k) ; if not isprime(a) and type(a, 'odd') then printf("%d, ", a) ; end if; end do: (End)

CROSSREFS

Cf. A002808, A141468.

Sequence in context: A087416 A216852 A068395 * A141557 A072563 A206011

Adjacent sequences:  A144583 A144584 A144585 * A144587 A144588 A144589

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Jan 04 2009

EXTENSIONS

Corrected at two or more places and extended by R. J. Mathar, May 01 2010

STATUS

approved

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Last modified April 19 05:22 EDT 2014. Contains 240738 sequences.