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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A151574 a(0)=1, a(1)=2; a(2^i + j) = a(j) + 2*a(j+1) for 0 <= j < 2^i.

Original entry on oeis.org

1, 2, 5, 12, 5, 12, 29, 22, 5, 12, 29, 22, 29, 70, 73, 32, 5, 12, 29, 22, 29, 70, 73, 32, 29, 70, 73, 80, 169, 216, 137, 42, 5, 12, 29, 22, 29, 70, 73, 32, 29, 70, 73, 80, 169, 216, 137, 42, 29, 70, 73, 80, 169, 216, 137, 90, 169, 216, 233, 418, 601, 490, 221, 52, 5, 12, 29, 22, 29
Offset: 0

Views

Author

N. J. A. Sloane, May 25 2009

Keywords

Comments

Equals 2*A151572 + A151703.

Crossrefs

For the recurrence a(2^i+j) = C*a(j) + D*a(j+1), a(0) = A, a(1) = B for following values of (A B C D) see: (0 1 1 1) A118977, (1 0 1 1) A151702, (1 1 1 1) A151570, (1 2 1 1) A151571, (0 1 1 2) A151572, (1 0 1 2) A151703, (1 1 1 2) A151573, (1 2 1 2) A151574, (0 1 2 1) A160552, (1 0 2 1) A151704, (1 1 2 1) A151568, (1 2 2 1) A151569, (0 1 2 2) A151705, (1 0 2 2) A151706, (1 1 2 2) A151707, (1 2 2 2) A151708.

Programs

  • Mathematica
    a = {1, 2}; Do[AppendTo[a, a[[j]] + 2 a[[j + 1]]], {i, 6}, {j, 2^i}]; a (* Ivan Neretin, Jun 28 2017 *)

A151704 a(0)=1, a(1)=0; a(2^i+j) = 2*a(j) + a(j+1) for 0 <= j < 2^i.

Original entry on oeis.org

1, 0, 2, 2, 2, 2, 6, 6, 2, 2, 6, 6, 6, 10, 18, 14, 2, 2, 6, 6, 6, 10, 18, 14, 6, 10, 18, 18, 22, 38, 50, 30, 2, 2, 6, 6, 6, 10, 18, 14, 6, 10, 18, 18, 22, 38, 50, 30, 6, 10, 18, 18, 22, 38, 50, 34, 22, 38, 54, 58, 82, 126, 130, 62, 2, 2, 6, 6, 6, 10, 18, 14, 6, 10, 18, 18, 22, 38, 50, 30, 6
Offset: 0

Views

Author

N. J. A. Sloane, Jun 06 2009

Keywords

Crossrefs

For the recurrence a(2^i+j) = C*a(j) + D*a(j+1), a(0) = A, a(1) = B for following values of (A B C D) see: (0 1 1 1) A118977, (1 0 1 1) A151702, (1 1 1 1) A151570, (1 2 1 1) A151571, (0 1 1 2) A151572, (1 0 1 2) A151703, (1 1 1 2) A151573, (1 2 1 2) A151574, (0 1 2 1) A160552, (1 0 2 1) A151704, (1 1 2 1) A151568, (1 2 2 1) A151569, (0 1 2 2) A151705, (1 0 2 2) A151706, (1 1 2 2) A151707, (1 2 2 2) A151708.

Programs

  • Maple
    See A151702 for Maple code.
  • Mathematica
    a = {1, 0}; Do[AppendTo[a, 2 a[[j]] + a[[j + 1]]], {i, 6}, {j, 2^i}]; a (* Ivan Neretin, Jul 04 2017 *)

A151705 a(0)=0, a(1)=1; a(2^i+j) = 2*a(j) + 2*a(j+1) for 0 <= j < 2^i.

Original entry on oeis.org

0, 1, 2, 6, 2, 6, 16, 16, 2, 6, 16, 16, 16, 44, 64, 36, 2, 6, 16, 16, 16, 44, 64, 36, 16, 44, 64, 64, 120, 216, 200, 76, 2, 6, 16, 16, 16, 44, 64, 36, 16, 44, 64, 64, 120, 216, 200, 76, 16, 44, 64, 64, 120, 216, 200, 104, 120, 216, 256, 368, 672, 832, 552, 156, 2, 6, 16, 16, 16
Offset: 0

Views

Author

N. J. A. Sloane, Jun 06 2009

Keywords

Crossrefs

For the recurrence a(2^i+j) = C*a(j) + D*a(j+1), a(0) = A, a(1) = B for following values of (A B C D) see: (0 1 1 1) A118977, (1 0 1 1) A151702, (1 1 1 1) A151570, (1 2 1 1) A151571, (0 1 1 2) A151572, (1 0 1 2) A151703, (1 1 1 2) A151573, (1 2 1 2) A151574, (0 1 2 1) A160552, (1 0 2 1) A151704, (1 1 2 1) A151568, (1 2 2 1) A151569, (0 1 2 2) A151705, (1 0 2 2) A151706, (1 1 2 2) A151707, (1 2 2 2) A151708.

Programs

  • Maple
    See A151702 for Maple code.
  • Mathematica
    a = {0, 1}; Do[AppendTo[a, 2 a[[j]] + 2 a[[j + 1]]], {i, 6}, {j, 2^i}]; a (* Ivan Neretin, Jul 04 2017 *)

A151706 a(0)=1, a(1)=0; a(2^i+j) = 2*a(j) + 2*a(j+1) for 0 <= j < 2^i.

Original entry on oeis.org

1, 0, 2, 4, 2, 4, 12, 12, 2, 4, 12, 12, 12, 32, 48, 28, 2, 4, 12, 12, 12, 32, 48, 28, 12, 32, 48, 48, 88, 160, 152, 60, 2, 4, 12, 12, 12, 32, 48, 28, 12, 32, 48, 48, 88, 160, 152, 60, 12, 32, 48, 48, 88, 160, 152, 80, 88, 160, 192, 272, 496, 624, 424, 124, 2, 4, 12, 12, 12, 32, 48
Offset: 0

Views

Author

N. J. A. Sloane, Jun 06 2009

Keywords

Crossrefs

For the recurrence a(2^i+j) = C*a(j) + D*a(j+1), a(0) = A, a(1) = B for following values of (A B C D) see: (0 1 1 1) A118977, (1 0 1 1) A151702, (1 1 1 1) A151570, (1 2 1 1) A151571, (0 1 1 2) A151572, (1 0 1 2) A151703, (1 1 1 2) A151573, (1 2 1 2) A151574, (0 1 2 1) A160552, (1 0 2 1) A151704, (1 1 2 1) A151568, (1 2 2 1) A151569, (0 1 2 2) A151705, (1 0 2 2) A151706, (1 1 2 2) A151707, (1 2 2 2) A151708.

Programs

  • Maple
    See A151702 for Maple code.
  • Mathematica
    a = {1, 0}; Do[AppendTo[a, 2 a[[j]] + 2 a[[j + 1]]], {i, 6}, {j, 2^i}]; a (* Ivan Neretin, Jul 04 2017 *)

A151707 a(0)=1, a(1)=1; a(2^i+j) = 2*a(j) + 2*a(j+1) for 0 <= j < 2^i.

Original entry on oeis.org

1, 1, 4, 10, 4, 10, 28, 28, 4, 10, 28, 28, 28, 76, 112, 64, 4, 10, 28, 28, 28, 76, 112, 64, 28, 76, 112, 112, 208, 376, 352, 136, 4, 10, 28, 28, 28, 76, 112, 64, 28, 76, 112, 112, 208, 376, 352, 136, 28, 76, 112, 112, 208, 376, 352, 184, 208, 376, 448, 640, 1168, 1456, 976, 280
Offset: 0

Views

Author

N. J. A. Sloane, Jun 06 2009

Keywords

Comments

Equals A151705 + A151706.

Crossrefs

For the recurrence a(2^i+j) = C*a(j) + D*a(j+1), a(0) = A, a(1) = B for following values of (A B C D) see: (0 1 1 1) A118977, (1 0 1 1) A151702, (1 1 1 1) A151570, (1 2 1 1) A151571, (0 1 1 2) A151572, (1 0 1 2) A151703, (1 1 1 2) A151573, (1 2 1 2) A151574, (0 1 2 1) A160552, (1 0 2 1) A151704, (1 1 2 1) A151568, (1 2 2 1) A151569, (0 1 2 2) A151705, (1 0 2 2) A151706, (1 1 2 2) A151707, (1 2 2 2) A151708.

Programs

  • Maple
    See A151702 for Maple code.
  • Mathematica
    a = {1, 1}; Do[AppendTo[a, 2 a[[j]] + 2 a[[j + 1]]], {i, 6}, {j, 2^i}]; a (* Ivan Neretin, Jul 04 2017 *)

A151708 a(0)=1, a(1)=2; a(2^i+j)=2*a(j)+2*a(j+1) for 0 <= j < 2^i.

Original entry on oeis.org

1, 2, 6, 16, 6, 16, 44, 44, 6, 16, 44, 44, 44, 120, 176, 100, 6, 16, 44, 44, 44, 120, 176, 100, 44, 120, 176, 176, 328, 592, 552, 212, 6, 16, 44, 44, 44, 120, 176, 100, 44, 120, 176, 176, 328, 592, 552, 212, 44, 120, 176, 176, 328, 592, 552, 288, 328, 592, 704, 1008, 1840, 2288
Offset: 0

Views

Author

N. J. A. Sloane, Jun 06 2009

Keywords

Comments

Equals 2*A151705+A151706.

Crossrefs

For the recurrence a(2^i+j) = C*a(j) + D*a(j+1), a(0) = A, a(1) = B for following values of (A B C D) see: (0 1 1 1) A118977, (1 0 1 1) A151702, (1 1 1 1) A151570, (1 2 1 1) A151571, (0 1 1 2) A151572, (1 0 1 2) A151703, (1 1 1 2) A151573, (1 2 1 2) A151574, (0 1 2 1) A160552, (1 0 2 1) A151704, (1 1 2 1) A151568, (1 2 2 1) A151569, (0 1 2 2) A151705, (1 0 2 2) A151706, (1 1 2 2) A151707, (1 2 2 2) A151708.

Programs

  • Maple
    See A151702 for Maple code.
  • Mathematica
    a = {1, 2}; Do[AppendTo[a, 2 a[[j]] + 2 a[[j + 1]]], {i, 6}, {j, 2^i}]; a (* Ivan Neretin, Jul 04 2017 *)

A169708 First differences of A169707.

Original entry on oeis.org

1, 4, 4, 12, 4, 12, 20, 28, 4, 12, 20, 28, 20, 44, 68, 60, 4, 12, 20, 28, 20, 44, 68, 60, 20, 44, 68, 76, 84, 156, 196, 124, 4, 12, 20, 28, 20, 44, 68, 60, 20, 44, 68, 76, 84, 156, 196, 124, 20, 44, 68, 76, 84, 156, 196, 140, 84, 156, 212, 236, 324, 508, 516, 252, 4, 12, 20, 28, 20
Offset: 0

Views

Author

N. J. A. Sloane, Apr 17 2010

Keywords

Examples

			From _Omar E. Pol_, Feb 13 2015: (Start)
Written as an irregular triangle in which row lengths are 1,1,2,4,8,16,32,... the sequence begins:
1;
4;
4,12;
4,12,20,28;
4,12,20,28,20,44,68,60;
4,12,20,28,20,44,68,60,20,44,68,76,84,156,196,124;
4,12,20,28,20,44,68,60,20,44,68,76,84,156,196,124,20,44,68,76,84,156,196,140,84,156,212,236,324,508,516,252;
It appears that the row sums give A000302.
It appears that the right border gives A173033.
(End)
		

Crossrefs

Formula

It appears that a(n) = 4*A160552(n), n >= 1. - Omar E. Pol, Feb 13 2015

Extensions

Initial 1 added by Omar E. Pol, Feb 13 2015

A256263 Triangle read by rows: T(j,k) = 2*k-1 if k is a power of 2, otherwise, between positions that are powers of 2 we have the initial terms of A016969, with j>=0, 1<=k<=A011782(j) and T(0,1) = 0.

Original entry on oeis.org

0, 1, 1, 3, 1, 3, 5, 7, 1, 3, 5, 7, 5, 11, 17, 15, 1, 3, 5, 7, 5, 11, 17, 15, 5, 11, 17, 23, 29, 35, 41, 31, 1, 3, 5, 7, 5, 11, 17, 15, 5, 11, 17, 23, 29, 35, 41, 31, 5, 11, 17, 23, 29, 35, 41, 47, 53, 59, 65, 71, 77, 83, 89, 63, 1, 3, 5, 7, 5, 11, 17, 15, 5, 11, 17, 23, 29, 35, 41, 31, 5, 11, 17, 23, 29, 35, 41, 47, 53, 59, 65, 71, 77, 83, 89
Offset: 0

Views

Author

Omar E. Pol, Mar 30 2015

Keywords

Comments

Partial sums give A256264.
First differs from A160552 at a(27).
Appears to be a canonical sequence partially related to the cellular automata of A139250, A147562, A162795, A169707, A255366, A256250. See also A256264 and A256260.

Examples

			Written as an irregular triangle in which the row lengths are the terms of A011782, the sequence begins:
0;
1;
1,3;
1,3,5,7;
1,3,5,7,5,11,17,15;
1,3,5,7,5,11,17,15,5,11,17,23,29,35,41,31;
1,3,5,7,5,11,17,15,5,11,17,23,29,35,41,31,5,11,17,23,29,35,41,47,53,59,65,71,77,83,89,63;
...
Right border gives A000225.
Apart from the initial 0 the row sums give A000302.
Rows converge to A256258.
.
Illustration of initial terms in the fourth quadrant of the square grid:
---------------------------------------------------------------------------
n   a(n)                 Compact diagram
---------------------------------------------------------------------------
0    0     _
1    1    |_|_ _
2    1      |_| |
3    3      |_ _|_ _ _ _
4    1          |_| | | |
5    3          |_ _| | |
6    5          |_ _ _| |
7    7          |_ _ _ _|_ _ _ _ _ _ _ _
8    1                  |_| | | |_ _  | |
9    3                  |_ _| | |_  | | |
10   5                  |_ _ _| | | | | |
11   7                  |_ _ _ _| | | | |
12   5                  | | |_ _ _| | | |
13  11                  | |_ _ _ _ _| | |
14  17                  |_ _ _ _ _ _ _| |
15  15                  |_ _ _ _ _ _ _ _|_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
16   1                                  |_| | | |_ _  | |_ _ _ _ _ _  | |
17   3                                  |_ _| | |_  | | |_ _ _ _ _  | | |
18   5                                  |_ _ _| | | | | |_ _ _ _  | | | |
19   7                                  |_ _ _ _| | | | |_ _ _  | | | | |
20   5                                  | | |_ _ _| | | |_ _  | | | | | |
21  11                                  | |_ _ _ _ _| | |_  | | | | | | |
22  17                                  |_ _ _ _ _ _ _| | | | | | | | | |
23  15                                  |_ _ _ _ _ _ _ _| | | | | | | | |
24   5                                  | | | | | | |_ _ _| | | | | | | |
25  11                                  | | | | | |_ _ _ _ _| | | | | | |
26  17                                  | | | | |_ _ _ _ _ _ _| | | | | |
27  23                                  | | | |_ _ _ _ _ _ _ _ _| | | | |
28  29                                  | | |_ _ _ _ _ _ _ _ _ _ _| | | |
29  35                                  | |_ _ _ _ _ _ _ _ _ _ _ _ _| | |
30  41                                  |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _| |
31  31                                  |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _|
.
a(n) is also the number of cells in the n-th region of the diagram.
A256264(n) gives the total number of cells after n-th stage.
		

Crossrefs

Programs

  • Mathematica
    Flatten@Join[{0}, NestList[Join[#, Range[Length[#] - 1]*6 - 1, {2 #[[-1]] + 1}] &, {1}, 6]] (* Ivan Neretin, Feb 14 2017 *)

Extensions

Terms a(95) to a(98) fixed by Ivan Neretin, Feb 14 2017

A162956 a(0) = 0, a(1) = 1; a(2^i + j) = 3a(j) + a(j + 1) for 0 <= j < 2^i.

Original entry on oeis.org

0, 1, 1, 4, 1, 4, 7, 13, 1, 4, 7, 13, 7, 19, 34, 40, 1, 4, 7, 13, 7, 19, 34, 40, 7, 19, 34, 46, 40, 91, 142, 121, 1, 4, 7, 13, 7, 19, 34, 40, 7, 19, 34, 46, 40, 91, 142, 121, 7, 19, 34, 46, 40, 91, 142, 127, 40, 91, 148, 178, 211, 415, 547, 364, 1, 4, 7, 13, 7, 19, 34, 40, 7, 19, 34, 46
Offset: 0

Views

Author

Gary W. Adamson, Jul 18 2009

Keywords

Comments

2^n term triangle by rows, analogous to A160552 but multiplier is "3" instead of "2"
Row sums = powers of 5: (1, 5, 25, 125, 625,...).
Rows tend to A162957, obtained by taking (1, 3, 0, 0, 0,...) * A162956.

Examples

			The triangle begins:
0;
1;
1, 4;
1, 4, 7, 13;
1, 4, 7, 13, 7, 19, 34, 40;
1, 4, 7, 13, 7, 19, 34, 40, 7, 19, 34, 46, 40, 91, 142, 121;
...
Row 4 = (1, 4, 7, 13, 7, 19, 34, 40): brings down (1, 4, 7, 13) then 7 = 3*1 + 4, 19 = 3*4 + 7, 34 = 3*7 + 13, 40 = 3*13 + 1.
		

Crossrefs

Programs

  • Maple
    a:= proc(n) option remember; `if`(n<2, n,
          (j-> 3*a(j)+a(j+1))(n-2^ilog2(n)))
        end:
    seq(a(n), n=0..100);  # Alois P. Heinz, Jan 28 2017
  • Mathematica
    row[0] = {0}; row[1] = {1}; row[n_] := row[n] = Join[row[n-1], 3 row[n-1] + Append[Rest[row[n-1]], 1]]; Table[row[n], {n, 0, 7}] // Flatten (* Jean-François Alcover, Mar 13 2017 *)

Formula

Follows the same analogous procedure as A160552 but multiplier is 3 instead of 2. (n+1)-th row brings down n-th row and appends to the right and equal number of terms following the rules: from left to right,let a = last term, b = current term, c = next term. Then c = 3*a + b except for the rightmost term = 3*a + 1.

Extensions

Edited with more terms by N. J. A. Sloane, Jan 02 2010

A162958 Equals A162956 convolved with (1, 3, 3, 3, ...).

Original entry on oeis.org

1, 4, 10, 19, 25, 40, 67, 94, 100, 115, 142, 175, 208, 280, 388, 469, 475, 490, 517, 550, 583, 655, 763, 850, 883, 955, 1069, 1201, 1372, 1696, 2101, 2344, 2350, 2365, 2392, 2425, 2458, 2530, 2638, 2725, 2758, 2830, 2944, 3076, 3247, 3571, 3976, 4225, 4258
Offset: 1

Views

Author

Gary W. Adamson, Jul 18 2009

Keywords

Comments

Can be considered a toothpick sequence for N=3, following rules analogous to those in A160552 (= special case of "A"), A151548 = special case "B", and the toothpick sequence A139250 (N=2) = special case "C".
To obtain the infinite set of toothpick sequences, (N = 2, 3, 4, ...), replace the multiplier "2" in A160552 with any N, getting a triangle with 2^n terms. Convolve this A sequence with (1, N, 0, 0, 0, ...) = B such that row terms of A triangles converge to B.
Then generalized toothpick sequences (C) = A convolved with (1, N, N, N, ...).
Examples: A160552 * (1, 2, 0, 0, 0,...) = a B-type sequence A151548.
A160552 * (1, 2, 2, 2, 2,...) = the toothpick sequence A139250 for N=2.
A162956 is analogous to A160552 but replaces "2" with the multiplier "3".
Row terms of A162956 tend to A162957 = (1, 3, 0, 0, 0, ...) * A162956.
Toothpick sequence for N = 3 = A162958 = A162956 * (1, 3, 3, 3, ...).
Row sums of "A"-type triangles = powers of (N+2); since row sums of A160552 = (1, 4, 16, 64, ...), while row sums of A162956 = (1, 5, 25, 125, ...).
Is there an illustration of this sequence using toothpicks? - Omar E. Pol, Dec 13 2016

Crossrefs

Third diagonal of A163311.

Programs

  • Maple
    b:= proc(n) option remember; `if`(n<2, n,
          (j-> 3*b(j)+b(j+1))(n-2^ilog2(n)))
        end:
    a:= proc(n) option remember;
          `if`(n=0, 0, a(n-1)+2*b(n-1)+b(n))
        end:
    seq(a(n), n=1..100);  # Alois P. Heinz, Jan 28 2017
  • Mathematica
    b[n_] := b[n] = If[n<2, n, Function[j, 3*b[j]+b[j+1]][n-2^Floor[Log[2, n]] ]];
    a[n_] := a[n] = If[n == 0, 0, a[n-1] + 2*b[n-1] + b[n]];
    Array[a, 100] (* Jean-François Alcover, Jun 11 2018, after Alois P. Heinz *)

Extensions

Clarified definition by Omar E. Pol, Feb 06 2017
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