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A269725
a(n) = row number of extended Wythoff array (see A035513) which contains the sequence n times the Fibonacci numbers 1,2,3,5,8,13,21,... .
10
0, 2, 3, 4, 15, 18, 21, 24, 27, 30, 33, 96, 104, 112, 120, 128, 136, 144, 152, 160, 168, 176, 184, 192, 200, 208, 216, 224, 232, 630, 651, 672, 693, 714, 735, 756, 777, 798, 819, 840, 861, 882, 903, 924, 945, 966, 987, 1008, 1029, 1050, 1071, 1092, 1113, 1134, 1155, 1176, 1197, 1218, 1239, 1260
OFFSET
1,2
REFERENCES
J. H. Conway, Posting to Math Fun Mailing List, Nov 25 1996.
LINKS
J. H. Conway, Allan Wechsler, Marc LeBrun, Dan Hoey, N. J. A. Sloane, On Kimberling Sums and Para-Fibonacci Sequences, Correspondence and Postings to Math-Fun Mailing List, Nov 1996 to Jan 1997
FORMULA
a(n) = A173027(n)-1. - R. J. Mathar, May 06 2017
EXAMPLE
Take n=5: 5 times 1,2,3,5,8,13,... gives 5,10,15,25,40,65,.., which is row 15 of the extended Wythoff array (when extended to the left), so a(5) = 15.
MAPLE
A269725 := proc(n)
local f, sl, r, c, wrks ;
f := [seq(n*combinat[fibonacci](i), i=2..30)] ;
for sl from 0 do
for r from 1 do
if A035513(r, 1) = op(1+sl, f) then
wrks := true;
for c from 2 to 5 do
if A035513(r, c) <> op(c+sl, f) then
wrks := false;
end if;
end do:
if wrks then
print(n, f, r) ;
return r-1 ;
end if;
elif A035513(r, 1) > op(1+sl, f) then
break ;
end if;
end do:
end do:
end proc: # R. J. Mathar, May 06 2017
MATHEMATICA
W[n_, k_] := Fibonacci[k+1] Floor[n*GoldenRatio] + (n-1) Fibonacci[k];
a[n_] := Module[{f, sl, r, c, wrks}, f = Table[n*Fibonacci[i], {i, 2, 30}]; For[sl = 0, True, sl++, For[r = 1, True, r++, Which[W[r, 1] == f[[1 + sl]], wrks = True; For[c = 2, c <= 5, c++, If[W[r, c] != f[[c+sl]], wrks = False]]; If[wrks, Return[r-1]], W[r, 1] > f[[1+sl]], Break[]]]]];
Table[a[n], {n, 1, 60}] (* Jean-François Alcover, Sep 13 2022, after R. J. Mathar *)
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Mar 07 2016
STATUS
approved