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.

Showing 1-9 of 9 results.

A265331 One-based row index to A265345.

Original entry on oeis.org

1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1, 5, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1, 7, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1, 5, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1, 6, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1, 5, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1, 7, 1, 2, 1, 3, 1, 2, 1, 5, 1, 2, 1, 3, 1, 2, 1, 5, 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1, 4
Offset: 1

Views

Author

Antti Karttunen, Dec 18 2015

Keywords

Crossrefs

One more than A265330.
Cf. A265911 (corresponding other index).
Differs from A001511 for the first time at n=32, where a(32) = 7, while A001511(32) = 6.

Programs

Formula

a(n) = A001511(A263273(n)).
a(2n+1) = 1, a(2n) = 1 + a(A265352(n)).

A265911 One-based column index to array A265345.

Original entry on oeis.org

1, 1, 2, 1, 4, 2, 3, 1, 5, 3, 10, 2, 7, 8, 11, 1, 13, 5, 8, 3, 6, 4, 20, 2, 9, 7, 14, 4, 28, 6, 19, 1, 29, 20, 37, 5, 22, 23, 12, 3, 58, 17, 25, 10, 38, 9, 31, 2, 16, 26, 32, 7, 40, 14, 23, 4, 17, 10, 65, 6, 24, 19, 15, 1, 56, 11, 21, 9, 47, 13, 59, 5, 26, 22, 18, 8, 74, 12, 27, 3, 41
Offset: 1

Views

Author

Antti Karttunen, Dec 18 2015

Keywords

Crossrefs

One more than A265910.
Cf. A265345.

Programs

Formula

a(n) = 1 + A265910(n).

A265330 Zero-based row index to A265345; 2-adic valuation of bijective base-3 reversal of n: a(n) = A007814(A263273(n)).

Original entry on oeis.org

0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 6, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, 3
Offset: 1

Views

Author

Antti Karttunen, Dec 18 2015

Keywords

Examples

			For n = 32, in base-3 "1012" [= A007089(32)], when we reverse it, we get "2101" [= A007089(64)], and 2-adic valuation of 64 [= "1000000" = A007088(64)] is 6, thus a(32) = 6.
		

Crossrefs

One less than A265331.
Cf. A265910 (corresponding other index).
Cf. also A265336, A265337, A265340.
Differs from A007814 for the first time at n=32, where a(32) = 6, while A007814(32) = 5.

Formula

a(n) = A007814(A263273(n)).
a(2n+1) = 0, a(2n) = 1 + a(A265352(n)).

A265910 Zero-based column index to array A265345.

Original entry on oeis.org

0, 0, 1, 0, 3, 1, 2, 0, 4, 2, 9, 1, 6, 7, 10, 0, 12, 4, 7, 2, 5, 3, 19, 1, 8, 6, 13, 3, 27, 5, 18, 0, 28, 19, 36, 4, 21, 22, 11, 2, 57, 16, 24, 9, 37, 8, 30, 1, 15, 25, 31, 6, 39, 13, 22, 3, 16, 9, 64, 5, 23, 18, 14, 0, 55, 10, 20, 8, 46, 12, 58, 4, 25, 21, 17, 7, 73, 11, 26, 2, 40
Offset: 1

Views

Author

Antti Karttunen, Dec 18 2015

Keywords

Crossrefs

One less than A265911.
Cf. A265345, A265352, A265354 (compare the scatter-plot).

Formula

a(2n+1) = A265354(n), a(2n) = a(A265352(n)).

A265346 Inverse permutation to A265345.

Original entry on oeis.org

1, 3, 2, 6, 7, 5, 4, 10, 11, 8, 46, 9, 22, 38, 56, 15, 79, 17, 29, 13, 16, 12, 191, 14, 37, 30, 92, 18, 379, 23, 172, 28, 407, 212, 667, 24, 232, 278, 67, 19, 1654, 155, 301, 69, 704, 47, 466, 20, 121, 353, 497, 39, 781, 107, 254, 25, 137, 57, 2081, 31, 277, 192, 106, 21, 1541, 68, 211, 58, 1082, 93, 1712, 32, 326, 255, 154, 48, 2702, 80, 352, 26, 821
Offset: 1

Views

Author

Antti Karttunen, Dec 18 2015

Keywords

Crossrefs

Inverse: A265345.

Programs

  • Scheme
    (define (A265346 n) (let ((col (A265911 n)) (row (A265331 n))) (* (/ 1 2) (- (expt (+ row col) 2) row col col col -2))))

Formula

a(n) = (1/2) * ((c+r)^2 - r - 3*c + 2), where c = A265911(n), and r = A265331(n).

A265347 Transpose of square array A265345.

Original entry on oeis.org

1, 2, 3, 4, 6, 7, 8, 12, 10, 5, 16, 24, 20, 22, 9, 64, 48, 40, 28, 18, 21, 32, 192, 80, 56, 36, 30, 13, 184, 96, 160, 112, 72, 60, 26, 19, 352, 552, 640, 224, 144, 120, 52, 14, 25, 704, 1056, 320, 448, 576, 240, 208, 76, 46, 11, 1408, 2112, 1600, 1720, 288, 480, 104, 136, 68, 58, 15
Offset: 1

Views

Author

Antti Karttunen, Dec 18 2015

Keywords

Comments

Square array A(row,col) is read by downwards antidiagonals as: A(0,0), A(0,1), A(1,0), A(0,2), A(1,1), A(2,0), A(0,3), A(1,2), A(2,1), A(3,0), ...
All the terms in the same row are either all divisible by 3, or none of them are.
Sequence A265345 is the main entry for this idea, please see further comment there.

Examples

			The top left corner of the array:
   1,  2,  4,   8,  16, 64,    32,  184,  352,   704,  1408, ...
   3,  6, 12,  24,  48, 192,   96,  552, 1056,  2112,  4224, ...
   7, 10, 20,  40,  80, 160,  640,  320, 1600,  3520,  6080, ...
   5, 22, 28,  56, 112, 224,  448, 1720,  824,  4936,  9856, ...
   9, 18, 36,  72, 144, 576,  288, 1656, 3168,  6336, 12672, ...
  21, 30, 60, 120, 240, 480, 1920,  960, 4800, 10560, 18240, ...
  13, 26, 52, 208, 104, 520, 1144, 2072, 3712, 16120,  6968, ...
  19, 14, 76, 136, 200, 256,  512, 1024, 6040,  3992, 15424, ...
  25, 46, 68,  88, 496, 344, 1984, 1376, 5344,  7768, 15224, ...
  11, 58, 44, 232, 424, 608,  736, 4384, 2936, 17536, 11744, ...
  ...
		

Crossrefs

Inverse permutation: A265348.
Transpose: A265345.

Programs

A265895 Square array: A(row,col) = A263273(A265345(row,col)) = 2^row * A263273(A265341(col)).

Original entry on oeis.org

1, 3, 2, 5, 6, 4, 7, 10, 12, 8, 9, 14, 20, 24, 16, 15, 18, 28, 40, 48, 32, 13, 30, 36, 56, 80, 96, 64, 11, 26, 60, 72, 112, 160, 192, 128, 17, 22, 52, 120, 144, 224, 320, 384, 256, 19, 34, 44, 104, 240, 288, 448, 640, 768, 512, 21, 38, 68, 88, 208, 480, 576, 896, 1280, 1536, 1024, 39, 42, 76, 136, 176, 416, 960, 1152, 1792, 2560, 3072, 2048
Offset: 1

Views

Author

Antti Karttunen, Dec 18 2015

Keywords

Comments

Square array A(row,col) is read by downwards antidiagonals as: A(0,0), A(0,1), A(1,0), A(0,2), A(1,1), A(2,0), A(0,3), A(1,2), A(2,1), A(3,0), ...
Shares with arrays A135764, A253551 and A254053 the property that odd terms are on the top row and when going downward in each column, terms grow by doubling.

Examples

			The top left corner of the array:
    1,   3,    5,    7,    9,   15,   13,   11,   17,   19,   21,   39,
    2,   6,   10,   14,   18,   30,   26,   22,   34,   38,   42,   78,
    4,  12,   20,   28,   36,   60,   52,   44,   68,   76,   84,  156,
    8,  24,   40,   56,   72,  120,  104,   88,  136,  152,  168,  312,
   16,  48,   80,  112,  144,  240,  208,  176,  272,  304,  336,  624,
   32,  96,  160,  224,  288,  480,  416,  352,  544,  608,  672, 1248,
   64, 192,  320,  448,  576,  960,  832,  704, 1088, 1216, 1344, 2496,
  128, 384,  640,  896, 1152, 1920, 1664, 1408, 2176, 2432, 2688, 4992,
  256, 768, 1280, 1792, 2304, 3840, 3328, 2816, 4352, 4864, 5376, 9984,
...
		

Crossrefs

Inverse permutation: A265896.
The top row: 1+(2*A263273(n)).
Differs from A135764 for the first time at n=16, where a(16) = 15, while A135764(16) = 11.

Formula

A(row,col) = A263273(A265345(row,col)).
A(row,col) = 2^row * A263273(A265341(col)).

A265341 Permutation of odd numbers: a(n) = 1 + (2*A265353(n)).

Original entry on oeis.org

1, 3, 7, 5, 9, 21, 13, 19, 25, 11, 15, 39, 17, 27, 63, 49, 57, 75, 31, 23, 67, 37, 55, 61, 43, 73, 79, 29, 33, 93, 47, 51, 147, 139, 111, 129, 35, 45, 117, 53, 81, 189, 157, 171, 225, 103, 69, 201, 145, 165, 183, 151, 219, 237, 85, 65, 193, 41, 71, 211, 121, 199, 205, 91, 59, 175, 109, 163, 169, 115, 181, 187, 97
Offset: 0

Views

Author

Antti Karttunen, Dec 07 2015

Keywords

Crossrefs

Topmost row of A265345.
Cf. A265353.
Cf. also A265342, A263273.

Programs

Formula

a(n) = 1 + (2*A265353(n)).

A264980 Base-3 reversal of 2^n: a(n) = A030102(A000079(n)).

Original entry on oeis.org

1, 2, 4, 8, 16, 64, 32, 184, 352, 704, 1408, 1880, 2824, 14032, 10328, 56128, 100576, 145784, 189472, 370304, 731752, 4388248, 2924096, 11175712, 15965704, 31930448, 63861880, 383165344, 255439712, 1021772344, 510875648, 2550188248, 5619691648, 9689861048, 17830350904, 79068724264, 34109913224, 192259976368, 133338241880
Offset: 0

Views

Author

Antti Karttunen, Dec 05 2015

Keywords

Examples

			2^5 = 32 in base 3 = "1012" (= A007089(32)) as 1*27 + 1*3 + 2*1 = 32. 2^6 = 64 in base 3 = "2101" as 2*27 + 1*9 + 1*1 = 64. "1012" reversed is "2101" and vice versa, thus a(5) = 64 and a(6) = 32.
		

Crossrefs

Leftmost column of A265345.
Cf. also A036215.

Programs

  • PARI
    base(n) = {my(a=[n%3]); while(0Altug Alkan, Dec 29 2015

Formula

a(n) = A030102(A000079(n)) = A263273(A000079(n)).
a(0) = 1, for n >= 1, a(n) = A265342(a(n-1)).
Showing 1-9 of 9 results.