The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A140776 A number n is included if (p + n/p) is prime, where p is the largest prime that divides n. 3
 2, 6, 10, 12, 22, 24, 28, 30, 34, 40, 42, 48, 52, 58, 60, 66, 70, 76, 78, 82, 84, 88, 90, 102, 112, 118, 120, 130, 132, 138, 142, 148, 160, 168, 172, 180, 184, 186, 190, 192, 198, 202, 204, 208, 210, 214, 220, 222, 228, 232, 234, 238, 240, 246, 252, 268, 270, 274 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All terms are even. - Robert Israel, Feb 04 2018 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 EXAMPLE The largest prime dividing 48 is 3. Since 3 + 48/3 = 19 is prime, then 48 is included in this sequence. MAPLE filter:= proc(n) local p;   p:= max(numtheory:-factorset(n));   isprime(p+n/p) end proc: select(filter, 2*[\$1..1000]); # Robert Israel, Feb 04 2018 MATHEMATICA fQ[n_] := Block[{p = Last@ First@ Transpose@ FactorInteger@n}, PrimeQ[p + n/p] == True]; Select[ Range[2, 279], fQ@# &] - Robert G. Wilson v, May 30 2008 CROSSREFS Cf. A140775, A140777. Sequence in context: A071638 A028348 A214963 * A277238 A108783 A235989 Adjacent sequences:  A140773 A140774 A140775 * A140777 A140778 A140779 KEYWORD nonn AUTHOR Leroy Quet, May 29 2008 EXTENSIONS More terms from Robert G. Wilson v, May 30 2008 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.

Last modified December 4 09:10 EST 2021. Contains 349484 sequences. (Running on oeis4.)