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A084424 Odd numbers having odd numbers of prime factors, odd sums of prime factors and odd sums of decimal digits. 1
3, 5, 7, 23, 27, 29, 41, 43, 47, 61, 67, 83, 89, 113, 131, 137, 139, 151, 157, 173, 179, 191, 193, 195, 197, 199, 223, 227, 229, 241, 243, 263, 269, 281, 283, 285, 311, 313, 317, 331, 337, 353, 357, 359, 373, 379, 397, 399, 401, 409, 421, 429, 443, 449, 461 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A020639(a(n)), A001221(a(n)), A001222(a(n)), A008472(a(n)), A001414(a(n)) and A007953(a(n)) are all odd.

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

EXAMPLE

9675 is odd, 9675 = 3^2 * 5^2 * 43: omega=3, Omega=5, sopf=3+5+43=51, sopfr=3+3+5+5+43=59 and SumOfDigits=9+6+7+5=27, therefore 9675 is a term.

MATHEMATICA

odQ[n_]:=And@@OddQ[{PrimeOmega[n], Total[IntegerDigits[n]], Total[ Transpose[ FactorInteger[n]][[1]]]}]; Select[Range[1, 501, 2], odQ] (* Harvey P. Dale, Jan 09 2014 *)

CROSSREFS

Sequence in context: A171015 A244571 A269721 * A137978 A155780 A296922

Adjacent sequences:  A084421 A084422 A084423 * A084425 A084426 A084427

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller, Jun 27 2003

STATUS

approved

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Last modified August 1 03:41 EDT 2021. Contains 346379 sequences. (Running on oeis4.)