cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A292959 Rectangular array by antidiagonals: T(n,m) = rank of n*(r+m) when all the numbers k*(r+h), where r = (1+sqrt(5))/2 (the golden ratio), k>=1, h>=0, are jointly ranked.

Original entry on oeis.org

1, 2, 3, 4, 7, 6, 5, 11, 13, 9, 8, 16, 21, 19, 14, 10, 22, 30, 31, 27, 18, 12, 28, 39, 45, 43, 36, 23, 15, 34, 50, 57, 61, 56, 44, 26, 17, 40, 60, 73, 79, 78, 68, 52, 32, 20, 47, 70, 87, 98, 101, 94, 83, 63, 37, 24, 54, 82, 104, 118, 126, 124, 113, 96, 72
Offset: 1

Views

Author

Clark Kimberling, Oct 05 2017

Keywords

Comments

This is the transpose of the array at A182849. Every positive integer occurs exactly once, so that as a sequence, this is a permutation of the positive integers.

Examples

			Northwest corner:
1    2    4    5     8     10    12    15
3    7    11   16    22    28    34    40
6    13   21   30    39    50    60    70
9    19   31   45    57    73    87    104
14   27   43   61    79    98    118   138
18   36   56   78    101   126   150   176
23   44   68   94    124   152   184   215
26   52   83   113   146   181   217   255
The numbers k*(r+h), approximately:
(for k=1):   1.618   2.618   3.618 ...
(for k=2):   3.236   5.236   7.236 ...
(for k=3):   4.854   7.854   10.854 ...
Replacing each by its rank gives
1     2      4
3     7      11
6     13     21
		

Crossrefs

Programs

  • Mathematica
    r = GoldenRatio; z = 12;
    t[n_, m_] := Sum[Floor[1 - r + n*(r + m)/k], {k, 1, Floor[n + m*n/r]}];
    u = Table[t[n, m], {n, 1, z}, {m, 0, z}]; TableForm[u]  (* A292959 array *)
    Table[t[n - k + 1, k - 1], {n, 1, z}, {k, n, 1, -1}] // Flatten  (* A292959 sequence *)

Formula

T(n,m) = Sum_{k=1...[n + m*n/r]} [1 - r + n*(r + m)/k], where r=GoldenRatio and [ ]=floor.

A292960 Rectangular array by antidiagonals: T(n,m) = rank of n*(r+m) when all the numbers k*(r+h), where r = ((1+sqrt(5))/2)^2, k>=1, h>=0, are jointly ranked.

Original entry on oeis.org

1, 2, 4, 3, 7, 9, 5, 11, 15, 13, 6, 16, 22, 23, 19, 8, 20, 29, 34, 32, 27, 10, 25, 38, 44, 47, 43, 33, 12, 30, 46, 57, 62, 61, 53, 40, 14, 36, 55, 69, 78, 81, 75, 66, 49, 17, 41, 65, 83, 95, 102, 100, 91, 76, 56, 18, 48, 74, 96, 112, 122, 124, 119, 107, 88
Offset: 1

Views

Author

Clark Kimberling, Oct 05 2017

Keywords

Comments

Every positive integer occurs exactly once, so that as a sequence, this is a permutation of the positive integers.

Examples

			Northwest corner:
1   2   3    5    6    8   10
4   7   11   16   20   25  30
9   15  22   29   38   46  55
13  23  34   44   57   69  83
19  32  47   62   78   95  112
27  43  61   81   102  122 145
The numbers k*(r+h), approximately:
(for k=1):   2.618   3.618   4.618 ...
(for k=2):   5.236   7.236   9.236 ...
(for k=3):   7.854   10.854   13.854 ...
Replacing each k*(r+h) by its rank gives
1    2     3
4    7     11
9    15    22
		

Crossrefs

Programs

  • Mathematica
    r = GoldenRatio^2; z = 12;
    t[n_, m_] := Sum[Floor[1 - r + n*(r + m)/k], {k, 1, Floor[n + m*n/r]}];
    u = Table[t[n, m], {n, 1, z}, {m, 0, z}]; TableForm[u]  (* A292960 array *)
    Table[t[n - k + 1, k - 1], {n, 1, z}, {k, n, 1, -1}] // Flatten  (* A292960 sequence *)

Formula

T(n,m) = Sum_{k=1...[n + m*n/r]} [1 - r + n*(r + m)/k], where r=(GoldenRatio)^2 and [ ]=floor.

A292961 Rectangular array by antidiagonals: T(n,m) = rank of n*(r+m) when all the numbers k*(r+h), where r = -1+(1+sqrt(5))/2, k>=1, h>=0, are jointly ranked.

Original entry on oeis.org

1, 3, 2, 6, 8, 4, 9, 15, 13, 5, 12, 22, 25, 19, 7, 17, 30, 38, 35, 27, 10, 20, 40, 52, 54, 48, 33, 11, 24, 49, 66, 74, 72, 61, 41, 14, 28, 58, 82, 93, 98, 91, 73, 46, 16, 32, 67, 96, 115, 124, 122, 108, 85, 55, 18, 37, 78, 111, 136, 151, 155, 146, 129, 101
Offset: 1

Views

Author

Clark Kimberling, Oct 05 2017

Keywords

Comments

Every positive integer occurs exactly once, so that as a sequence, this is a permutation of the positive integers.

Examples

			Northwest corner:
1    3    6    9    12   17   20
2    8    15   22   30   40   49
4    13   25   38   52   66   82
5    19   35   54   74   93   115
7    27   48   72   98   124  151
10   33   61   91   122  155  190
11   41   73   108  146  187  226
14   46   85   129  172  218  266
The numbers k*(r+h), approximately:
(for k=1):   0.618   1.618   2.618 ...
(for k=2):   1.236   3.236   5.236 ...
(for k=3):   1.854   4.854   7.854 ...
Replacing each k*(r+h) by its rank gives
1    3    6
2    8    15
4    13   25
		

Crossrefs

Programs

  • Mathematica
    r = -1+GoldenRatio; z = 12;
    t[n_, m_] := Sum[Floor[1 - r + n*(r + m)/k], {k, 1, Floor[n + m*n/r]}];
    u = Table[t[n, m], {n, 1, z}, {m, 0, z}]; TableForm[u]  (* A292961 array *)
    Table[t[n - k + 1, k - 1], {n, 1, z}, {k, n, 1, -1}] // Flatten  (* A292961 sequence *)

Formula

T(n,m) = Sum_{k=1...[n + m*n/r]} [1 - r + n*(r + m)/k], where r=1/GoldenRatio and [ ]=floor.

A178431 Joint-rank array of the sums of two primes.

Original entry on oeis.org

1, 2, 2, 4, 3, 4, 6, 5, 5, 6, 9, 7, 7, 7, 9, 11, 10, 8, 8, 10, 11, 14, 12, 12, 10, 12, 12, 14, 16, 15, 13, 13, 13, 13, 15, 16, 19, 17, 17, 15, 17, 15, 17, 17, 19, 23, 20, 18, 18, 18, 18, 18, 18, 20, 23, 25, 24, 21, 20, 21, 20, 21, 20, 21, 24, 25
Offset: 1

Views

Author

Clark Kimberling, Dec 21 2010

Keywords

Comments

Joint-rank arrays are defined at A157927 for arrays in which duplicates occur (and otherwise, at A182801).

Examples

			A corner of the array A178400 of sums of two primes:
4...5...7...9..13...
5...6...8..10..14...
7...8..10..12..14...
9..10..12..14..18...
Each of these P(i,j) is replaced by its rank when all the
numbers P(h,k) are jointly ranked, leaving A178431:
1...2...4...6...9...
2...3...5...7..10...
4...5...7...8..12...
6...7...8..10..13...
The number of distinct sums p+q <=13 is 9.
		

Crossrefs

A182802 Joint-rank array of the numbers j*(1+tau)^2*(i-1), where tau = golden ratio = (1+sqrt(5))/2, i>=1, read by antidiagonals.

Original entry on oeis.org

1, 2, 3, 4, 7, 9, 5, 11, 20, 26, 6, 15, 31, 55, 72, 8, 19, 42, 84, 148, 194, 10, 23, 53, 113, 224, 393, 515, 12, 28, 64, 142, 300, 592, 1036, 1357, 13, 32, 75, 171, 376, 791, 1557, 2721, 3563, 14, 36, 86, 200, 452, 990, 2078, 4085, 7134, 9340
Offset: 1

Views

Author

Clark Kimberling, Dec 05 2010

Keywords

Comments

Joint-rank arrays are defined in the first comment at A182801. There r=tau; here r=1+tau=(tau)^2.
(Column 1)=A054963. Every positive integer occurs exactly once, so that as a sequence, A182802 is a permutation of the positive integers.

Examples

			Northwest corner:
1....2....4....5....6...
3....7...11...15...19...
9...20...31...42...53...
26..55...84..113..142...
		

Crossrefs

Cf. A182801.

Formula

T(i,j)=SUM{floor(j*(tau)^(2*(i-n))): n>=1}.

A182831 Joint-rank array of numbers j*r^(i-1), where r=1+sqrt(2), read by antidiagonals.

Original entry on oeis.org

1, 2, 3, 4, 6, 8, 5, 11, 17, 22, 7, 14, 28, 45, 55, 9, 19, 37, 70, 112, 137, 10, 23, 48, 93, 171, 276, 334, 12, 26, 57, 118, 228, 417, 671, 812, 13, 31, 66, 141, 287, 556, 1010, 1627, 1965, 15, 34, 77, 164, 344, 697, 1347, 2444, 3934, 4751, 16, 39
Offset: 1

Views

Author

Clark Kimberling, Dec 07 2010

Keywords

Comments

Joint-rank arrays are defined in the first comment at A182801. (row 1)=A087063. First 3 columns are A020062, A020063, A020064.
Every positive integer occurs exactly once, so that as a sequence, this is a permutation of the positive integers.

Examples

			Northwest corner:
   1  2  4  5 ...
   3  6 11 14 ...
   8 17 28 37 ...
  22 45 70 93 ...
  ...
		

Crossrefs

Cf. A182801.

Programs

  • Mathematica
    T[n_, k_] := Sum[Floor[k*(1 + Sqrt[2])^(n - j)], {j, 1, 100}]; Table[T[k + 1, n - k], {n,1,10}, {k, 0, n-1}]//Flatten (* G. C. Greubel, Aug 18 2018 *)

Formula

T(i,j) = Sum_{n>=1} floor(j*(1+sqrt(2))^(i-n)).

A182832 Joint-rank array of numbers j*r^(i-1), where r=1+sqrt(3), read by antidiagonals.

Original entry on oeis.org

1, 2, 3, 4, 7, 10, 5, 12, 21, 30, 6, 15, 34, 61, 85, 8, 19, 44, 95, 172, 237, 9, 24, 56, 125, 262, 476, 652, 11, 28, 68, 157, 347, 718, 1307, 1788, 13, 32, 80, 190, 435, 955, 1965, 3579, 4891, 14, 37, 91, 222, 524, 1196, 2618, 5373, 9786, 13371, 16, 41, 104
Offset: 1

Views

Author

Clark Kimberling, Dec 07 2010

Keywords

Comments

Joint-rank arrays are defined in the first comment at A182801. Every positive integer occurs exactly once, so that as a sequence A182832 is a permutation of the positive integers.

Examples

			Northwest corner:
1....2....4....5....6...
3....7...12...15...19...
10..21...34...44...56...
30..61...95..125..157...
		

Crossrefs

Cf. A182801.

Formula

T(i,j)=SUM{floor(j*(1+sqrt(3))^(i-n)): n>=1}.

A182949 Joint-rank array of the numbers (3*i+1)*3^j, where i>=0, j>=0, by antidiagonals.

Original entry on oeis.org

1, 2, 3, 5, 7, 4, 14, 19, 11, 6, 41, 55, 32, 16, 8, 122, 163, 95, 46, 21, 9, 365, 487, 284, 136, 60, 25, 10, 1094, 1459, 851, 406, 177, 73, 29, 12, 3281, 4375, 2552, 1216, 528, 217, 86, 34, 13, 9842, 13123, 7655, 3646, 1581, 649, 257, 100, 38, 15
Offset: 1

Views

Author

Clark Kimberling, Dec 15 2010

Keywords

Comments

Joint-rank arrays are defined in the first comment at A182801. As for any joint-rank array, A182949 is a permutation of the positive integers, but, a fortiori, A182949 is an interspersion: after initial terms every row is interspersed with all other rows. The numbers (3*i+1)*3^j as an array comprise A182828; and sorted, A026225.
(row 1)=A007051.
(row 2)=A052919.
(col 1)=A182829.

Examples

			Northwest corner:
1....2....5....14...
3....7...19....55...
4...11...32....95...
6...16...46...136...
		

Crossrefs

Programs

  • Mathematica
     M[i_,j_]:=j+Floor[Log[3*i+1]/Log[3]]; T[i_,j_]:=Sum[Floor[2/3+(3*i+1)*3^(j-k-1)],{k,0,M[i,j]}]; TableForm[Table[T[i,j],{i,0,9},{j,0,9}]]

A182950 Joint-rank array of the numbers (3*i+2)*3^j, where i>=0, j>=0, by antidiagonals.

Original entry on oeis.org

1, 3, 2, 9, 7, 4, 27, 22, 12, 5, 81, 67, 36, 16, 6, 243, 202, 108, 49, 20, 8, 729, 607, 324, 148, 62, 25, 10, 2187, 1822, 972, 445, 188, 76, 30, 11, 6561, 5467, 2916, 1336, 566, 229, 90, 34, 13, 19683, 16402, 8748, 4009, 1700, 688, 270, 103, 39, 14
Offset: 1

Views

Author

Clark Kimberling, Dec 15 2010

Keywords

Comments

Joint-rank arrays are defined in the first comment at A182801. As for any joint-rank array, A182950 is a permutation of the positive integers, but, a fortiori, A182950 is an interspersion: after initial terms every row is interspersed with all other rows. The numbers (3*i+2)*3^j as an array comprise A182830; and sorted, possibly A026179.
(row 1)=A000244.
(row 2)=A060816.
(row 3)=A003946.
(row 4)=A052909.
(row 5)=A027107?

Examples

			Northwest corner:
1....3....9....27...
2....7...22....67...
4...12...36...108...
5...16...49...148...
		

Crossrefs

Programs

  • Mathematica
     M[i_,j_]:=j+Floor[Log[3*i/2+1]/Log[3]];
     T[i_,j_]:=Sum[Floor[1/3+(3*i+2)*3^(j-k-1)],{k,0,M[i,j]}];
     TableForm[Table[T[i,j],{i,0,9},{j,0,9}]]

A252229 The number of numbers j*r^k in the interval [n,n+1), where r = (1 + sqrt(5))/2, the golden ratio, and j >=0, k >= 0.

Original entry on oeis.org

1, 2, 2, 2, 3, 2, 3, 2, 3, 2, 2, 3, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 3, 2, 2, 3, 2, 3, 2, 4, 2, 2, 2, 4, 3, 3, 2, 2, 3, 2, 2, 3, 3, 2, 3, 2, 4, 3, 2, 2, 3, 2, 2, 3, 3, 4, 2, 2, 3, 3, 2, 3, 2, 3, 2, 2, 3, 3, 3, 2, 2, 3, 3, 2, 2, 3, 4, 3, 2, 2, 3, 2, 3, 2, 3, 2
Offset: 0

Views

Author

Clark Kimberling, Dec 16 2014

Keywords

Comments

The least n for which a(n) = 4 is 29; the least n for which a(n) = 5 is 199.

Examples

			in [0,1):  0
in [1,2):  1, 1 + r
in [2,3):  2, 2 + r
in [3,4):  3, 1+2*r
in [4,5):  4, 1+3*r, 2 + r
		

Crossrefs

Programs

  • Mathematica
    z = 100; r = (1 + Sqrt[5])/2;
    s[n_, j_] := s[n, j] = Floor[Log[n/j]/Log[r]];
    a[n_] := a[n] = Sum[s[n + 1, j] - s[n, j], {j, 1, Floor[(n + 1)/r]}];
    t = Join[{1}, Table[1 + a[n], {n, 1, z}]] (* A252229 *)

Formula

a(n) = 1 + sum{s(n+1,j) - s(n,j), j=1..floor[(n+1)/r]}, where s(n,j) = floor[log(n/j)/log(r)], for n >= 1.
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