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Index of first occurrence of n in A005229.
2

%I #21 Jan 01 2024 11:19:59

%S 1,3,4,6,7,8,10,12,13,14,16,17,19,20,21,22,24,26,27,29,31,32,33,34,36,

%T 37,39,40,41,43,46,47,48,49,50,51,53,55,56,58,59,60,61,63,64,67,69,70,

%U 71,72,73,74,75,77,80,81,82,83,85,87,88,89,90,92,94,95,98,99,100,102

%N Index of first occurrence of n in A005229.

%F a(n) = least k such that A005229(k) = n.

%o (True BASIC)

%o 70 DIM q0(0 to 4000)

%o 80 LET q0(1)=1

%o 90 LET q0(2)=1

%o 91 FOR n = 3 to 4000

%o 92 LET q0(n)=q0(q0(n-2))+q0(n-q0(n-2))

%o 93 NEXT n

%o 100 SET MODE "color"

%o 110 SET WINDOW 0,1024,0,750

%o 302 PRINT" by _Roger L. Bagula_ 2 OCT. 2003"

%o 303 DIM p(0 to 4000)

%o 310 FOR x=1 to 4000

%o 311 REM if p(q0(x)) hasn't been used already give p() a value

%o 312 IF p(q0(x))=0 then LET p(q0(x))=x

%o 380 NEXT x

%o 381 OPEN #1: name "CM1:MI_data",create newold, org text

%o 390 FOR x=1 to 200

%o 391 PRINT #1: p(x);",";

%o 392 PRINT p(x);

%o 393 NEXT x

%o 394 CLOSE #1

%o 460 END

%o (PARI) {m=102;v5229=vector(m);v5229[1]=1;v5229[2]=1;for(k=3,m,v5229[k]=v5229[v5229[k-2]]+v5229[k-v5229[k-2]]); v=vector(m);for(j=1,m,if(v[v5229[j]]==0,v[v5229[j]]=j));n=0;while(v[n++ ]>0,print1(v[n],","))}

%Y Cf. A005229.

%K nonn

%O 1,2

%A _Roger L. Bagula_, Oct 02 2003

%E Edited by _N. J. A. Sloane_, Apr 07 2006