login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A219955 Numbers that cannot be represented as 2*p + 3*q, where p and q are prime. 7
1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 14, 17, 18, 22, 24, 26, 30, 33, 34, 36, 38, 42, 46, 48, 50, 51, 54, 56, 58, 60, 62, 66, 69, 70, 72, 74, 76, 78, 81, 82, 84, 86, 87, 90, 94, 96, 98, 102, 104, 105, 106, 108, 110, 111, 114, 116, 118, 120, 122, 123, 126, 130, 132 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Numbers not in A079026.

LINKS

Zak Seidov, Table of n, a(n) for n = 1..1000

FORMULA

a(n) < 1.5n + O(n/log n). - Charles R Greathouse IV, Dec 04 2012

MATHEMATICA

mx = 200; Complement[Range[mx], Flatten@Table[2 Prime[i] + 3 Prime[k], {k, PrimePi[(mx - 4)/3]}, {i, PrimePi[(mx - 3 Prime[k])/2]}]] (* Zak Seidov, Dec 04 2012 *)

PROG

(PARI) list(lim)=my(v=vectorsmall(lim\1), u=List()); forprime(p=2, lim\2, forprime(q=2, (lim-2*p)\3, v[2*p+3*q]=1)); for(i=1, #v, if(!v[i], listput(u, i))); Vec(u) \\ Charles R Greathouse IV, Dec 04 2012

CROSSREFS

Cf. A079026.

Sequence in context: A085429 A202940 A082324 * A079064 A123176 A017902

Adjacent sequences:  A219952 A219953 A219954 * A219956 A219957 A219958

KEYWORD

nonn

AUTHOR

Zak Seidov, Dec 02 2012

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 15 14:36 EDT 2019. Contains 327078 sequences. (Running on oeis4.)