

A072592


Even numbers with at least one prime factor of form 4*k+1.


3



10, 20, 26, 30, 34, 40, 50, 52, 58, 60, 68, 70, 74, 78, 80, 82, 90, 100, 102, 104, 106, 110, 116, 120, 122, 130, 136, 140, 146, 148, 150, 156, 160, 164, 170, 174, 178, 180, 182, 190, 194, 200, 202, 204, 208, 210, 212, 218, 220, 222, 226, 230, 232, 234, 238
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OFFSET

1,1


COMMENTS

A072591(a(n)) = 0.
Conjecture: this is exactly the sequence whose terms are twice those of A009003. (This has been verified for all terms<=500.) Compare A009003.  John W. Layman, Mar 12 2008
The conjecture is true. See comments on A008846 and A004613.  Lambert Herrgesell (zero815(AT)googlemail.com), Apr 24 2008


LINKS

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


MATHEMATICA

opfQ[n_]:=Count[Transpose[FactorInteger[n]][[1]], _?(IntegerQ[ (#1)/4]&)]>0; Select[Range[2, 250, 2], opfQ] (* Harvey P. Dale, Jun 02 2012 *)


CROSSREFS

Cf. A005843, A002144.
Sequence in context: A342142 A179819 A320522 * A229305 A229304 A101869
Adjacent sequences: A072589 A072590 A072591 * A072593 A072594 A072595


KEYWORD

nonn


AUTHOR

Reinhard Zumkeller, Jun 23 2002


STATUS

approved



