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A007071 First row of 2-shuffle of spectral array W( sqrt 2 ).
(Formerly M0616)
1
1, 2, 3, 5, 6, 7, 9, 11, 12, 13, 15, 16, 17, 19, 21, 22, 23, 25, 26, 27, 29, 30, 31, 33, 35, 36, 37, 39, 40, 41, 43, 45, 46, 47, 49, 50, 51, 53, 54, 55, 57, 59, 60, 61, 63, 64, 65, 67, 69, 70, 71, 73, 74, 75, 77, 79, 80, 81, 83, 84, 85, 87, 88, 89, 91, 93, 94, 95, 97, 98, 99, 101 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Aviezri S. Fraenkel and Clark Kimberling, Generalized Wythoff arrays, shuffles and interspersions, Discr. Math. 126 (1-3) (1994) 137-149. [From R. J. Mathar, Aug 17 2009]
MAPLE
Digits := 200 : WythSpec := proc(n, x) floor(n*x) ; end: A001951 := proc(n) WythSpec(n, sqrt(2)) ; end: A001952 := proc(n) A001951(n)+2*n; end: Wsqrt2 := proc(i, j) option remember ; if j = 1 then A001951(A001951(i)) ; elif j = 2 then A001952(A001951(i)) ; elif type(j, 'odd') then A001951(procname(i, j-1)) ; else A001952(procname(i, j-2)) ; fi; end: A007071 := proc(n) option remember ; local a; if n = 1 then 1; else for a from procname(n-1)+1 do for k from 1 do if Wsqrt2(k, 1) = a then RETURN(a); elif Wsqrt2(k, 1) > a then break; fi; od: for k from 1 do if Wsqrt2(k, 2) = a then RETURN(a); elif Wsqrt2(k, 2) > a then break; fi; od: od: fi; end: seq(A007071(n), n=1..100) ; # R. J. Mathar, Aug 17 2009
MATHEMATICA
WythSpec[n_, x_] := Floor[n*x] ;
A001951[n_] := WythSpec[n, Sqrt[2]];
A001952[n_] := A001951[n] + 2n;
WSqrt2[i_, j_] := WSqrt2[i, j] = Which[j == 1, A001951[A001951[i]], j == 2, A001952[A001951[i]], OddQ[j], A001951[WSqrt2[i, j-1]], True, A001952[WSqrt2[i, j-2]]];
A007071[n_] := A007071[n] = Module[{a, k}, If[n == 1, 1, For[a = A007071[n-1]+1, True, a++, For[k = 1, True, k++, If[WSqrt2[k, 1] == a, Return[a], If[WSqrt2[k, 1] > a, Break[]]]]; For[k = 1, True, k++, If[WSqrt2[k, 2] == a, Return[a], If[WSqrt2[k, 2] > a, Break[]]]]]]];
Table[A007071[n], {n, 1, 72}] (* Jean-François Alcover, Dec 20 2023, after R. J. Mathar *)
CROSSREFS
Sequence in context: A057196 A080637 A124134 * A242482 A085784 A085783
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
More terms from R. J. Mathar, Aug 17 2009
STATUS
approved

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Last modified April 21 01:42 EDT 2024. Contains 371850 sequences. (Running on oeis4.)