OFFSET
1,1
MAPLE
A075331 := proc(nmax) local r, s, n, stst, rtst, i ; r := [1] : s := [] : n := {1} : while nops(r) < nmax do stst := 1 ; while stst in n or stst-op(-1, r) in n or stst+op(-1, r) in n do stst := stst +1 ; od ; s := [op(s), stst] ; n := n union {stst, stst-op(-1, r), stst+op(-1, r)} ; rtst := 1 ; while rtst in n do rtst := rtst +1 ; od ; r := [op(r), rtst] ; n := n union {rtst} ; od : for i from 1 to nops(s) do s := subsop(i=op(i, r)+op(i, s), s) ; od ; RETURN(s) ; end: A075331(100) ; # R. J. Mathar, Feb 03 2007
MATHEMATICA
A075331[nmax_] := Module[{r = {1}, s = {}, n = {1}, stst, rtst}, While[Length[r] < nmax, stst = 1; While[MemberQ[n, stst] || MemberQ[n, stst - Last[r]] || MemberQ[n, stst + Last[r]], stst++]; s = Append[s, stst]; n = n~Union~{stst, stst - Last[r], stst + Last[r]}; rtst = 1; While[MemberQ[n, rtst], rtst++]; r = Append[r, rtst]; n = n~Union~{rtst}]; Return[Most[r] + s]];
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Sep 18 2002
EXTENSIONS
More terms from R. J. Mathar, Feb 03 2007
STATUS
approved