This site is supported by donations to The OEIS Foundation.

 Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS". Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A045954 Even-Lucky-Numbers (ELN): generated by a sieve process like that for Lucky numbers but starting with even numbers. 19
 2, 4, 6, 10, 12, 18, 20, 22, 26, 34, 36, 42, 44, 50, 52, 54, 58, 68, 70, 76, 84, 90, 98, 100, 102, 108, 114, 116, 118, 130, 132, 138, 140, 148, 150, 164, 170, 172, 178, 182, 186, 196, 198, 212, 214, 218, 228, 230, 234, 244, 246, 260, 262, 268, 278, 282, 290, 298, 300, 308 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Write down even numbers: 2 4 6 8 ...; first term > 2 is 4 so starting from 2 remove every 4th number: 2 4 6 10 12 14 18...; next number is 6 so remove every 6th term starting from 2: 2 4 6 10 12 18 20 22 26 etc. LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..1000 MAPLE ## Finds all Even Lucky Numbers up to n from the list 2...n. ## Try n=10^5 or 10^6 just for fun! evenluckynumbers:=proc(n) local k, Lnext, Lprev; Lprev:=[\$2..n]; for k from 1 do Lnext:= map(w-> Lprev[w], remove(z -> z mod Lprev[k] = 0, [\$1..nops(Lprev)])); if nops(Lnext)=nops(Lprev) then return Lnext fi; Lprev:=Lnext; od; end: # Walter Kehowski, Jun 06 2008 MATHEMATICA lst = Range[2, 308, 2]; i = 2; While[ i <= (len = Length@lst) && (k = lst[[i]]) <= len, lst = Drop[lst, {k, len, k}]; i++ ]; lst (* Robert G. Wilson v, May 11 2006 *) PROG (Haskell) a045954 n = a045954_list !! (n-1) a045954_list =  2 : sieve 2 [2, 4..] where    sieve k xs = z : sieve (k + 1) (lucky xs) where       z = xs !! (k - 1 )       lucky ws = us ++ lucky vs where             (us, _:vs) = splitAt (z - 1) ws -- Reinhard Zumkeller, Dec 05 2011 CROSSREFS Cf. A000959, A039672. Sequence in context: A033098 A220478 A033868 * A072542 A167856 A162578 Adjacent sequences:  A045951 A045952 A045953 * A045955 A045956 A045957 KEYWORD nice,nonn,easy AUTHOR 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.