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 A022941 a(n) = a(n-1) + c(n-2) for n >= 3, a( ) increasing, given a(1)=1, a(2)=2; where c( ) is complement of a( ). 5
 1, 2, 5, 9, 15, 22, 30, 40, 51, 63, 76, 90, 106, 123, 141, 160, 180, 201, 224, 248, 273, 299, 326, 354, 383, 414, 446, 479, 513, 548, 584, 621, 659, 698, 739, 781, 824, 868, 913, 959, 1006, 1054, 1103, 1153, 1205, 1258, 1312, 1367, 1423, 1480, 1538 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Except for a(2), identical to A022940. - Ivan Neretin, Apr 05 2016 LINKS Nathaniel Johnston, Table of n, a(n) for n = 1..10000 MAPLE a[1]:=1: a[2]:=2: c[1]:=3: for n from 2 to 70 do c[n]:=c[n-1]+1: for k from 1 to n do if(c[n]<=a[k])then if(c[n]=a[k])then c[n]:=c[n]+1: fi: break: fi: od: a[n+1]:=a[n]+c[n-1]: od: seq(a[n], n=1..70); # Nathaniel Johnston, May 01 2011 MATHEMATICA Fold[Append[#1, #1[[-1]] + Complement[Range[Max@#1 + 1], #1][[#2]]] &, {1, 2}, Range[50]] (* Ivan Neretin, Apr 04 2016 *) PROG (Haskell) import Data.List (delete) a022941 n = a022941_list !! (n-1) a022941_list = 1 : 2 : f 2 [3..] where    f x (z:zs) = y : f y (delete y zs) where y = x + z -- Reinhard Zumkeller, May 17 2013 CROSSREFS Cf. A143344 (first differences), A156031. Cf. A005228 and references therein. Sequence in context: A033096 A195014 A152738 * A007982 A011904 A218914 Adjacent sequences:  A022938 A022939 A022940 * A022942 A022943 A022944 KEYWORD nonn AUTHOR EXTENSIONS a(27) inserted by Nathaniel Johnston, May 01 2011 STATUS approved

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