A228041
Decimal expansion of sum of reciprocals, row 3 of Wythoff array, W = A035513.
Original entry on oeis.org
4, 2, 9, 9, 4, 2, 8, 3, 3, 1, 2, 1, 5, 8, 8, 7, 7, 6, 5, 8, 6, 0, 0, 5, 6, 5, 1, 4, 5, 9, 4, 6, 3, 5, 8, 9, 8, 4, 4, 4, 5, 2, 5, 6, 6, 8, 6, 5, 9, 8, 4, 2, 4, 3, 2, 4, 7, 7, 7, 6, 9, 0, 7, 6, 6, 2, 5, 6, 5, 1, 5, 9, 4, 9, 8, 3, 4, 1, 6, 9, 1, 8, 0, 7, 7, 0
Offset: 0
1/6 + 1/10 + 1/16 + ... = 0.4299428331215887765860056514594635898444...
-
f[n_] := f[n] = Fibonacci[n]; g = GoldenRatio; w[n_, k_] := w[n, k] = f[k + 1]*Floor[n*g] + f[k]*(n - 1);
n = 3; Table[w[n, k], {n, 1, 5}, {k, 1, 5}]
r = N[Sum[1/w[n, k], {k, 1, 2000}], 120]
RealDigits[r, 10]
A228042
Decimal expansion of sum of reciprocals, row 4 of Wythoff array, W = A035513.
Original entry on oeis.org
2, 8, 6, 6, 2, 8, 5, 5, 5, 4, 1, 4, 3, 9, 2, 5, 1, 7, 7, 2, 4, 0, 0, 3, 7, 6, 7, 6, 3, 9, 6, 4, 2, 3, 9, 3, 2, 2, 9, 6, 3, 5, 0, 4, 4, 5, 7, 7, 3, 2, 2, 8, 2, 8, 8, 3, 1, 8, 5, 1, 2, 7, 1, 7, 7, 5, 0, 4, 3, 4, 3, 9, 6, 6, 5, 5, 6, 1, 1, 2, 7, 8, 7, 1, 8, 0
Offset: 0
1/9 + 1/15 + 1/24 + ... = 0.28662855541439251772400376763964239322963...
-
f[n_] := f[n] = Fibonacci[n]; g = GoldenRatio; w[n_, k_] := w[n, k] = f[k + 1]*Floor[n*g] + f[k]*(n - 1);
n = 4; Table[w[n, k], {n, 1, 5}, {k, 1, 5}]
r = N[Sum[1/w[n, k], {k, 1, 2000}], 120]
RealDigits[r, 10]
A228043
Decimal expansion of sum of reciprocals, row 5 of Wythoff array, W = A035513.
Original entry on oeis.org
2, 1, 4, 9, 7, 1, 4, 1, 6, 5, 6, 0, 7, 9, 4, 3, 8, 8, 2, 9, 3, 0, 0, 2, 8, 2, 5, 7, 2, 9, 7, 3, 1, 7, 9, 4, 9, 2, 2, 2, 2, 6, 2, 8, 3, 4, 3, 2, 9, 9, 2, 1, 2, 1, 6, 2, 3, 8, 8, 8, 4, 5, 3, 8, 3, 1, 2, 8, 2, 5, 7, 9, 7, 4, 9, 1, 7, 0, 8, 4, 5, 9, 0, 3, 8, 5
Offset: 0
1/12 + 1/20 + 1/32 + ... = 0.21497141656079438829300282572973179492222...
-
f[n_] := f[n] = Fibonacci[n]; g = GoldenRatio; w[n_, k_] := w[n, k] = f[k + 1]*Floor[n*g] + f[k]*(n - 1);
n = 5; Table[w[n, k], {n, 1, 5}, {k, 1, 5}]
r = N[Sum[1/w[n, k], {k, 1, 2000}], 120]
RealDigits[r, 10]
A255671
Number of the column of the Wythoff array (A035513) that contains U(n), where U = A001950, the upper Wythoff sequence.
Original entry on oeis.org
2, 4, 2, 2, 6, 2, 4, 2, 2, 4, 2, 2, 8, 2, 4, 2, 2, 6, 2, 4, 2, 2, 4, 2, 2, 6, 2, 4, 2, 2, 4, 2, 2, 10, 2, 4, 2, 2, 6, 2, 4, 2, 2, 4, 2, 2, 8, 2, 4, 2, 2, 6, 2, 4, 2, 2, 4, 2, 2, 6, 2, 4, 2, 2, 4, 2, 2, 8, 2, 4, 2, 2, 6, 2, 4, 2, 2, 4, 2, 2, 6, 2, 4, 2, 2, 4
Offset: 1
Corner of the Wythoff array:
1 2 3 5 8 13
4 7 11 18 29 47
6 10 16 26 42 68
9 15 24 39 63 102
L = (1,3,4,6,8,9,11,...); U = (2,5,7,10,13,15,18,...), so that
A255670 = (1,3,1,1,5,...) and A255671 = (2,4,2,2,6,...).
-
z = 13; r = GoldenRatio; f[1] = {1}; f[2] = {1, 2};
f[n_] := f[n] = Join[f[n - 1], Most[f[n - 2]], {n}]; f[z];
g[n_] := g[n] = f[z][[n]]; Table[g[n], {n, 1, 100}] (* A035612 *)
Table[g[Floor[n*r]], {n, 1, (1/r) Length[f[z]]}] (* A255670 *)
Table[g[Floor[n*r^2]], {n, 1, (1/r^2) Length[f[z]]}] (* A255671 *)
A269729
a(n) = row number of extended Wythoff array (see A035513) which contains the sequence obtained by reading the n-th row backwards (and adjusting signs).
Original entry on oeis.org
0, 1, 2, 3, 4, 7, 10, 5, 8, 11, 6, 9, 12, 20, 28, 15, 23, 31, 18, 26, 13, 21, 29, 16, 24, 32, 19, 27, 14, 22, 30, 17, 25, 33, 54, 75, 41, 62, 83, 49, 70, 36, 57, 78, 44, 65, 86, 52, 73, 39, 60, 81, 47, 68, 34, 55, 76, 42, 63, 84, 50, 71, 37, 58, 79, 45, 66, 87, 53, 74, 40
Offset: 0
Take n=5: reading row 5 of A035513 backwards gives ... 23, 14, 9, 5, 4, 1, 3, -2, 5, -7, 12, -19, ..., which after adjusting the signs is row 7, so a(5) = 7.
- J. H. Conway, Postings to Math Fun Mailing List, Nov 25 1996 and Dec 02 1996.
-
A035513 := proc(r::integer, c::integer)
option remember;
if c = 1 then
A003622(r) ;
elif c > 1 then
A022342(1+procname(r, c-1)) ;
elif c < 1 then
procname(r,c+2)-procname(r,c+1) ;
end if;
end proc:
# search in A035513 for row with consecutive w1,w2
A035513inv := proc(w1::integer,w2::integer)
local r,c,W1,W2 ;
for r from 1 do
if A035513(r,1) > w2 then
return -1 ;
end if;
for c from 1 do
W1 := A035513(r,c) ;
W2 := A035513(r,c+1) ;
if W1=w1 and W2=w2 then
return r-1 ;
elif W2 > w2 then
break;
end if;
end do:
end do:
end proc:
A269729 := proc(n)
option remember;
local c,W1,W2,r,n35513;
n35513 := n+1 ;
for c from 1 by -1 do
W1 := A035513(n35513,c) ;
W2 := A035513(n35513,c-1) ;
if W1 < 0 and abs(W2) > abs(W1) then
r := A035513inv(abs(W1),abs(W2)) ;
if r >= 0 then
return r;
end if;
end if;
end do:
end proc:
seq(A269729(n),n=0..120) ; # R. J. Mathar, May 08 2019
-
W[n_, k_] := W[n, k] = Fibonacci[k+1] Floor[n*GoldenRatio] + (n-1)* Fibonacci[k];
Winv[w1_, w2_] := Winv[w1, w2] = Module[{r, c, W1, W2}, For[r = 1, True, r++, If[W[r, 1] > w2, Return[-1]]; For[c = 1, True, c++, W1 = W[r, c]; W2 = W[r, c+1]; If[W1 == w1 && W2 == w2, Return[r-1], If[W2 > w2, Break[]]]]]];
a[n_] := a[n] = Module[{c, W1, W2, r, nw}, nw = n+1; For[c = 1, True, c--, W1 = W[nw, c]; W2 = W[nw, c-1]; If[W1 < 0 && Abs[W2] > Abs[W1], r = Winv[Abs[W1], Abs[W2]]; If[r >= 0, Return[r]]]]];
Table[Print[n, " ", a[n]]; a[n], {n, 0, 120}] (* Jean-François Alcover, Aug 09 2023, after R. J. Mathar *)
A274286
Numbers that are a product of distinct numbers in row 2 of the Wythoff array, A035513.
Original entry on oeis.org
4, 7, 11, 18, 28, 29, 44, 47, 72, 76, 77, 116, 123, 126, 188, 198, 199, 203, 304, 308, 319, 322, 329, 492, 504, 517, 521, 522, 532, 792, 796, 812, 836, 843, 846, 861, 1276, 1288, 1316, 1353, 1363, 1364, 1368, 1386, 1393, 2068, 2084, 2088, 2128, 2189, 2204
Offset: 1
-
f[1] = 4; f[2] = 7; z = 33; f[n_] := f[n - 1] + f[n - 2]; f = Table[f[n], {n, 1, z}]; f
s = {1}; Do[s = Union[s, Select[s*f[[i]], # <= f[[z]] &]], {i, z}]; s1 = Rest[s]
A274287
Numbers that are a product of distinct numbers in row 3 of the Wythoff array, A035513.
Original entry on oeis.org
6, 10, 16, 26, 42, 60, 68, 96, 110, 156, 160, 178, 252, 260, 288, 408, 416, 420, 466, 660, 672, 680, 754, 960, 1068, 1088, 1092, 1100, 1220, 1560, 1728, 1760, 1768, 1780, 1974, 2496, 2520, 2796, 2848, 2856, 2860, 2880, 3194, 4032, 4080, 4160, 4524, 4608
Offset: 1
60 = 6*10, 960 = 6*10*16.
-
f[1] = 6; f[2] = 10; z = 33; f[n_] := f[n - 1] + f[n - 2]; f = Table[f[n], {n, 1, z}]; f
s = {1}; Do[s = Union[s, Select[s*f[[i]], # <= f[[z]] &]], {i, z}]; Rest[s]
A328695
Rectangular array R read by descending antidiagonals: divide to each even term of the Wythoff array (A035513) by 2, and delete all others.
Original entry on oeis.org
1, 4, 2, 17, 9, 3, 72, 38, 5, 12, 305, 161, 8, 51, 6, 1292, 682, 13, 216, 10, 7, 5473, 2889, 21, 915, 16, 30, 14, 23184, 12238, 34, 3876, 26, 127, 59, 25, 98209, 51841, 55, 16419, 42, 538, 250, 106, 11, 416020, 219602, 89, 69552, 68, 2279, 1059, 449, 18, 33
Offset: 1
Row 1 of the Wythoff array is (1,2,3,5,8,13,21,34,55,89,144,...), so that row 1 of R is (1,4,17,72,...).
_______________
Northwest corner of R:
1 4 17 72 305 1292 5473
2 9 38 161 682 2889 12238
3 5 8 13 21 34 55
12 51 216 915 3876 16419 69552
6 10 16 26 42 68 110
7 30 127 538 2279 9654 40895
Cf.
A035513,
A001076,
A001077,
A000045,
A115179,
A006355,
A097924,
A048875,
A000032,
A328696,
A328697.
-
w[n_, k_] := Fibonacci[k + 1] Floor[n*GoldenRatio] + (n - 1) Fibonacci[k];
Table[w[n - k + 1, k], {n, 12}, {k, n, 1, -1}] // Flatten;
q[n_, k_] := If[Mod[w[n, k], 2] == 0, w[n, k]/2, 0];
t[n_] := Union[Table[q[n, k], {k, 1, 50}]];
u[n_] := If[First[t[n]] == 0, Rest[t[n]], t[n]]
Table[u[n], {n, 1, 10}] (* A328695 array *)
v[n_, k_] := u[n][[k]];
Table[v[n - k + 1, k], {n, 12}, {k, n, 1, -1}] // Flatten (* A328695 sequence *)
A328696
Rectangular array R read by descending antidiagonals: apply x -> (x+1)/2 to each odd term of the Wythoff array (A035513), and delete all others.
Original entry on oeis.org
1, 2, 4, 3, 6, 5, 7, 15, 8, 12, 11, 24, 20, 19, 9, 28, 62, 32, 49, 23, 10, 45, 100, 83, 79, 37, 16, 13, 117, 261, 134, 206, 96, 41, 21, 14, 189, 422, 350, 333, 155, 66, 54, 36, 25, 494, 1104, 566, 871, 405, 172, 87, 58, 40, 17, 799, 1786, 1481, 1409, 655
Offset: 1
Row 1 of the Wythoff array is (1,2,3,5,8,13,21,34,55,89,144,...), so that row 1 of R is (1,2,3,7,11,...) = A107857 (essentially).
_______________
Northwest corner of R:
1, 2, 3, 7, 11, 28, 45, 117, 189, 494, 799
4, 6, 15, 24, 62, 100, 261, 422, 1104, 1786, 4675
5, 8, 20, 32, 83, 134, 350, 566, 1481, 2396, 6272
12, 19, 49, 79, 206, 333, 871, 1409, 3688, 5967, 15621
9, 23, 37, 96, 155, 405, 655, 1714, 2773, 7259, 11745
10, 16, 41, 66, 172, 278, 727, 1176, 3078, 4980, 13037
13, 21, 54, 87, 227, 367, 960, 1553, 4065, 6577, 17218
-
w[n_, k_] := Fibonacci[k + 1] Floor[n*GoldenRatio] + (n - 1) Fibonacci[k];
Table[w[n - k + 1, k], {n, 12}, {k, n, 1, -1}] // Flatten;
q[n_, k_] := If[Mod[w[n, k], 2] == 1, (1 + w[n, k])/2, 0];
t[n_] := Union[Table[q[n, k], {k, 1, 50}]];
u[n_] := If[First[t[n]] == 0, Rest[t[n]], t[n]]
s = Select[Range[40], ! u[#] == {} &]; u1[n_] := u[s[[n]]];
Column[Table[u1[n], {n, 1, 10}]] (* A328696 array *)
v[n_, k_] := u1[n][[k]];
Table[v[n - k + 1, k], {n, 12}, {k, n, 1, -1}] // Flatten (* A328696 sequence *)
A360377
a(n) = number of the row of the Wythoff array (A035513) that includes prime(n).
Original entry on oeis.org
1, 1, 1, 2, 2, 1, 7, 8, 6, 2, 8, 6, 10, 17, 2, 21, 23, 24, 26, 11, 7, 12, 20, 1, 6, 39, 40, 10, 26, 17, 49, 8, 53, 21, 14, 36, 6, 63, 40, 10, 69, 27, 7, 46, 76, 2, 81, 33, 54, 88, 1, 92, 14, 23, 38, 64, 66, 42, 27, 74, 18, 80, 84, 53, 54, 90, 94, 59, 60, 24
Offset: 1
The 10th prime is 29, which occurs in row 7, so a(10) = 2.
-
W[n_, k_] := Fibonacci[k + 1] Floor[n*GoldenRatio] + (n - 1) Fibonacci[k];
t = Table[W[n, k], {n, 100}, {k, 1, 20}];
a[n_] := Select[Range[100], MemberQ[t[[#]], Prime[n]] &]
Flatten[Table[a[n], {n, 1, 100}]]
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