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A099355
From P-positions in a certain game.
3
0, 4, 10, 14, 21, 25, 27, 31, 33, 38, 44, 48, 55, 59, 61, 65, 67, 71, 74, 78, 84, 89, 92, 96, 102, 107, 110, 114, 120, 124, 131, 135, 137, 141, 143, 148, 154, 158, 165, 169, 171, 175, 177, 181, 184, 188, 194, 199, 202, 206, 212, 217, 220, 224, 230, 235, 237
OFFSET
0,2
LINKS
A. S. Fraenkel, New games related to old and new sequences, INTEGERS, Electronic J. of Combinatorial Number Theory, Vol. 4, Paper G6, 2004.
FORMULA
See A099354.
MAPLE
a:=proc(n) option remember: local j, t: if(n=0)then return 0: else t:=a(n-1)+1: for j from 0 to n-1 do if(t=b(j))then return t+1: elif(t<b(j))then break: fi: od: return t: fi: end:
b:=proc(n) option remember: if(n=0)then return 0: else return b(n-1) - a(n-1) + a(n) + (-1)^b(n-1) - (-1)^a(n-1) + 3: fi: end:
seq(b(n), n=0..70); # Nathaniel Johnston, Apr 28 2011
MATHEMATICA
a[n_] := a[n] = Module[{j, t}, If[n == 0, 0, t = a[n - 1] + 1; For[j = 0, j <= n - 1, j++, Which[t == b[j], Return[t + 1], t < b[j], Break[]]]; t]];
b[n_] := b[n] = If[n == 0, 0, b[n - 1] - a[n - 1] + a[n] + (-1)^b[n - 1] - (-1)^a[n - 1] + 3];
Table[b[n], {n, 0, 70}] (* Jean-François Alcover, Mar 10 2023, after Nathaniel Johnston *)
CROSSREFS
Sequence in context: A114335 A302087 A329103 * A161366 A310424 A176551
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Nov 16 2004
STATUS
approved