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 1-10 of 12 results. Next

A191323 Increasing sequence generated by these rules: a(1)=1, and if x is in a then [3x/2]+1 and 3x+1 are in a, where [ ]=floor.

Original entry on oeis.org

1, 2, 4, 7, 11, 13, 17, 20, 22, 26, 31, 34, 40, 47, 52, 61, 67, 71, 79, 92, 94, 101, 103, 107, 119, 121, 139, 142, 152, 155, 157, 161, 179, 182, 184, 202, 209, 214, 229, 233, 236, 238, 242, 269, 274, 277, 283, 304, 310, 314, 322, 344, 350, 355, 358, 364, 404, 412, 416, 418, 425, 427, 457, 466, 472, 484, 517, 526, 533, 538, 547, 553
Offset: 1

Views

Author

Clark Kimberling, May 30 2011

Keywords

Comments

This sequence represents a class of sequences generated by rules of the form "a(1)=1, and if x is in a then floor(hx+i) and floor(jx+k) are in a, where h and j are rational numbers and i and k are positive integers." In the following examples, the floor function is denoted by [ ].
A191323: [3x/2]+1, 3x+1
A191324: [3x/2]+1, 3x+2
A191325: [3x/2], [5x/2]
A191326: [3x/2], [7x/2]
A191327: [5x/2], [7x/2]
A191328: [5x/3], [7x/3]
Other families of sequences generated by "rules" are listed at A191803, A191106, A101113 and A191203.

Examples

			1 -> 2,4 -> 6,7,13 -> 10,11,19,20,22,40 -> ...
		

Crossrefs

Programs

  • Mathematica
    h = 3; i = 1; j = 3; k = 1; f = 1; g = 12;
    a=Union[Flatten[NestList[{Floor[h#/2]+i,j#+k}&,f,g]]]
    (* A191323 *)

A191211 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 1+2x and 1+x^2 are in a.

Original entry on oeis.org

1, 2, 3, 5, 7, 10, 11, 15, 21, 23, 26, 31, 43, 47, 50, 53, 63, 87, 95, 101, 107, 122, 127, 175, 191, 203, 215, 226, 245, 255, 351, 383, 407, 431, 442, 453, 491, 511, 530, 677, 703, 767, 815, 863, 885, 907, 962, 983, 1023, 1061, 1355, 1407, 1535, 1631, 1727, 1771, 1815, 1850, 1925, 1967, 2047, 2123, 2210, 2501
Offset: 1

Views

Author

Clark Kimberling, May 29 2011

Keywords

Comments

See A191203.

Examples

			1 -> 2,3 -> 5,7,10 ->
		

Crossrefs

Cf. A191203.

Programs

  • Haskell
    import Data.Set (singleton, deleteFindMin, insert)
    a191211 n = a191211_list !! (n-1)
    a191211_list = f $ singleton 1 where
       f s = m : f (insert (2 * m + 1) $ insert (m ^ 2 + 1) s')
             where (m, s') = deleteFindMin s
    -- Reinhard Zumkeller, Apr 18 2014
  • Mathematica
    g = 11; Union[Flatten[NestList[{1 + 2 #, 1 + #^2} &, 1, g]]]
    (* A191211; use g>10 to get all of first 60 terms *)

A191281 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 2x and x^2-x+1 are in a.

Original entry on oeis.org

1, 2, 3, 4, 6, 7, 8, 12, 13, 14, 16, 24, 26, 28, 31, 32, 43, 48, 52, 56, 57, 62, 64, 86, 96, 104, 112, 114, 124, 128, 133, 157, 172, 183, 192, 208, 224, 228, 241, 248, 256, 266, 314, 344, 366, 384, 416, 448, 456, 482, 496, 512, 532, 553, 628, 651, 688, 732, 757, 768, 832, 896, 912, 931, 964, 992, 993, 1024, 1064, 1106, 1256, 1302
Offset: 1

Views

Author

Clark Kimberling, May 29 2011

Keywords

Comments

See A191203.

Examples

			1 -> 2 -> 3,4 -> 6,7,8,13 ->
		

Crossrefs

Cf. A191203.

Programs

  • Mathematica
    g = 12; Union[Flatten[NestList[{2 #, #^2 - # + 1} &, 1, g]]]
    (* A191281; use g>11 to get all of first 60 terms *)

A191282 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 2x and x^2+x+1 are in a.

Original entry on oeis.org

1, 2, 3, 4, 6, 7, 8, 12, 13, 14, 16, 21, 24, 26, 28, 32, 42, 43, 48, 52, 56, 57, 64, 73, 84, 86, 96, 104, 112, 114, 128, 146, 157, 168, 172, 183, 192, 208, 211, 224, 228, 256, 273, 292, 314, 336, 344, 366, 384, 416, 422, 448, 456, 463, 512, 546, 584, 601, 628, 672, 688, 703, 732, 768, 813, 832, 844, 896, 912, 926, 1024, 1057, 1092
Offset: 1

Views

Author

Clark Kimberling, May 29 2011

Keywords

Comments

See A191203.

Examples

			1 -> 2,3 -> 4,6,7,13 ->
		

Crossrefs

Cf. A191203.

Programs

  • Mathematica
    g = 11; Union[Flatten[NestList[{2 #, #^2 + # + 1} &, 1, g]]]
    (* A191282; use g>10 to get all of first 60 terms *)

A191283 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 2x and x(x+1)/2 are in a.

Original entry on oeis.org

1, 2, 3, 4, 6, 8, 10, 12, 16, 20, 21, 24, 32, 36, 40, 42, 48, 55, 64, 72, 78, 80, 84, 96, 110, 128, 136, 144, 156, 160, 168, 192, 210, 220, 231, 256, 272, 288, 300, 312, 320, 336, 384, 420, 440, 462, 512, 528, 544, 576, 600, 624, 640, 666, 672, 768, 820, 840, 880, 903, 924, 1024, 1056, 1088, 1152, 1176, 1200, 1248, 1280, 1332
Offset: 1

Views

Author

Clark Kimberling, May 29 2011

Keywords

Comments

See A191203.

Examples

			1 -> 2 -> 3,4 -> 6,8,10 ->
		

Crossrefs

Cf. A191203.

Programs

  • Mathematica
    g = 12; Union[Flatten[NestList[{2 #, (#^2 + #)/2} &, 1, g]]]
    (* A191283; use g>10 to get all of first 60 terms *)

A191284 Increasing sequence generated by these rules: a(1)=1, and if x is in a then floor(3x/2) and 2x are in a.

Original entry on oeis.org

1, 2, 3, 4, 6, 8, 9, 12, 13, 16, 18, 19, 24, 26, 27, 28, 32, 36, 38, 39, 40, 42, 48, 52, 54, 56, 57, 58, 60, 63, 64, 72, 76, 78, 80, 81, 84, 85, 87, 90, 94, 96, 104, 108, 112, 114, 116, 117, 120, 121, 126, 127, 128, 130, 135, 141, 144, 152, 156, 160, 162, 168, 170, 171, 174, 175, 180, 181, 188, 189, 190, 192, 195, 202, 208, 211, 216
Offset: 1

Views

Author

Clark Kimberling, May 29 2011

Keywords

Comments

See A191203.

Examples

			1 -> 2,3 -> 4,6 -> 8,9,12 ->
		

Crossrefs

Cf. A191203.

Programs

  • Mathematica
    g=16; Union[Flatten[NestList[{Floor[3 #/2], 2#} &, 1, g]]]
    (* A191284; use g>15 to get all of first 60 terms *)

A191285 Increasing sequence S generated by these rules: 1 is in S, and if x is in S then 3x and floor((x^2)/2) are in S.

Original entry on oeis.org

0, 1, 3, 4, 8, 9, 12, 24, 27, 32, 36, 40, 72, 81, 96, 108, 120, 216, 243, 288, 324, 360, 364, 512, 648, 729, 800, 864, 972, 1080, 1092, 1536, 1944, 2187, 2400, 2592, 2916, 3240, 3276, 3280, 4608, 5832, 6561, 7200, 7776, 8748, 9720, 9828, 9840, 13824, 17496, 19683, 21600, 23328, 26244, 29160, 29484, 29520, 29524
Offset: 1

Views

Author

Clark Kimberling, May 29 2011

Keywords

Comments

See A191203.

Examples

			1 -> 0,3 -> 4,8,9,27 ->
		

Crossrefs

Cf. A191203.

Programs

  • Mathematica
    g=12; Union[Flatten[NestList[{3#,Floor[(#^2)/2]}&,1,g]]]
    (* A191285; use g>11 to get all of first 60 terms *)

A191286 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 3x and 1+x^2 are in a.

Original entry on oeis.org

1, 2, 3, 5, 6, 9, 10, 15, 18, 26, 27, 30, 37, 45, 54, 78, 81, 82, 90, 101, 111, 135, 162, 226, 234, 243, 246, 270, 303, 325, 333, 405, 486, 677, 678, 702, 729, 730, 738, 810, 901, 909, 975, 999, 1215, 1370, 1458, 2026, 2031, 2034, 2106, 2187, 2190, 2214, 2430, 2703, 2727, 2917, 2925, 2997, 3645, 4110, 4374
Offset: 1

Views

Author

Clark Kimberling, May 29 2011

Keywords

Comments

See A191203.

Examples

			1 -> 2,3 -> 5,6,9,10 ->
		

Crossrefs

Cf. A191203.

Programs

  • Mathematica
    g = 10; Union[Flatten[NestList[{3 #, 1 + #^2} &, 1, g]]]
    (* A191286; use g>9 to get all of first 60 terms *)

A191287 Increasing sequence generated by these rules: a(1)=1, and if x is in a then floor(3x/2) and 3x are in a.

Original entry on oeis.org

1, 3, 4, 6, 9, 12, 13, 18, 19, 27, 28, 36, 39, 40, 42, 54, 57, 58, 60, 63, 81, 84, 85, 87, 90, 94, 108, 117, 120, 121, 126, 127, 130, 135, 141, 162, 171, 174, 175, 180, 181, 189, 190, 195, 202, 211, 243, 252, 255, 256, 261, 262, 270, 271, 282, 283, 285, 292, 303, 316, 324, 351, 360, 363, 364, 378, 381, 382, 384, 390, 391, 393, 405
Offset: 1

Views

Author

Clark Kimberling, May 29 2011

Keywords

Comments

See A191203.

Examples

			1 -> 3 -> 4,9 -> 6,12,13,27 ->
		

Crossrefs

Cf. A191203.

Programs

  • Mathematica
    g=15; Union[Flatten[NestList[{Floor[3#/2],3#} &, 1, g]]]
    (* A191287; use g>14 to get all of first 60 terms *)

A191288 Increasing sequence generated by these rules: 1 is in a, and if x is in a then 2x and floor((x^2)/3) are in a.

Original entry on oeis.org

0, 1, 2, 4, 5, 8, 10, 16, 20, 21, 32, 33, 40, 42, 64, 66, 80, 84, 85, 128, 132, 133, 147, 160, 168, 170, 256, 264, 266, 294, 320, 336, 340, 341, 363, 512, 528, 532, 533, 588, 640, 672, 680, 682, 726, 1024, 1056, 1064, 1066, 1176, 1280, 1344, 1360, 1364, 1365, 1452, 2048, 2112, 2128, 2132, 2133, 2352, 2408, 2560, 2688, 2720
Offset: 1

Views

Author

Clark Kimberling, May 29 2011

Keywords

Comments

See A191203.

Examples

			1 -> {0,2} -> 4 -> {5,8} -> {10,16,21} -> ...
		

Crossrefs

Cf. A191203.

Programs

  • Mathematica
    g=13; Union[Flatten[NestList[{2#, Floor[(#^2)/3]}&,1,g]]]
    (* A191288; use g>12 to get all of first 60 terms *)

Extensions

Definition corrected by Han Guoniu, Oct 11 2012
Showing 1-10 of 12 results. Next