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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A118532 Start with 1 and repeatedly reverse the digits and add 15 to get the next term.

Original entry on oeis.org

1, 16, 76, 82, 43, 49, 109, 916, 634, 451, 169, 976, 694, 511, 130, 46, 79, 112, 226, 637, 751, 172, 286, 697, 811, 133, 346, 658, 871, 193, 406, 619, 931, 154, 466, 679, 991, 214, 427, 739, 952, 274, 487, 799, 1012, 2116, 6127, 7231, 1342, 2446
Offset: 1

Views

Author

N. J. A. Sloane, May 06 2006

Keywords

Comments

This sequence never cycles.
The plot (see the Noe link) shows 2774 terms of this sequence. It has a regular structure, which continues at higher decades. - T. D. Noe, May 10 2006

Crossrefs

Programs

  • Haskell
    a118532 n = a118532_list !! (n-1)
    a118532_list = iterate ((+ 15) . a004086) 1
    -- Reinhard Zumkeller, Jan 29 2014
  • PARI
    A118532(Nmax,Q=15,S=1)=vector(Nmax,i,if(i>1,S=A004086(S)+Q,S)) \\ - M. F. Hasler, May 06 2012
    

Formula

This sequence never cycles. After a while, the pattern of length changes settles into an increasing pattern: 10^(4m)+3, 10^(4m+1)+3, 10^(4m+2)+12, 10^(4m+3)+12, 10^(4(m+1))+3, ... The key is that every two steps adds 15 at each end, unless there is a carry across the middle or a trailing 0. This allows many steps to be carried out in a single operation. - Martin Fuller, May 12 2006
a(n+1) = A004086(a(n)) + 15. - Reinhard Zumkeller, Jan 29 2014

A118879 Let T(S,Q) be the sequence obtaining by starting with S and repeatedly reversing the digits and adding Q to get the next term. This is T(1016,5), the first S for which T(S,5) reaches a cycle of length 36.

Original entry on oeis.org

1016, 6106, 6021, 1211, 1126, 6216, 6131, 1321, 1236, 6326, 6241, 1431, 1346, 6436, 6351, 1541, 1456, 6546, 6461, 1651, 1566, 6656, 6571, 1761, 1676, 6766, 6681, 1871, 1786, 6876, 6791, 1981, 1896, 6986, 6901, 1101, 1016, 6106, 6021
Offset: 0

Views

Author

N. J. A. Sloane, May 26 2006

Keywords

Comments

The cycle is simply the first 36 terms, which then repeat.
For S < 1016, T(S,5) reaches a cycle of length 207 (cf. A117800).

Crossrefs

Programs

  • Mathematica
    NestList[IntegerReverse[#]+5&,1016,40] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Mar 05 2020 *)

A118529 Start with 1 and repeatedly reverse the digits and add 12 to get the next term.

Original entry on oeis.org

1, 13, 43, 46, 76, 79, 109, 913, 331, 145, 553, 367, 775, 589, 997, 811, 130, 43, 46, 76, 79, 109, 913, 331, 145, 553, 367, 775, 589, 997, 811, 130, 43, 46, 76, 79, 109, 913, 331, 145, 553, 367, 775, 589, 997, 811, 130, 43, 46, 76, 79, 109, 913, 331
Offset: 1

Views

Author

N. J. A. Sloane, May 06 2006

Keywords

Crossrefs

Programs

  • Mathematica
    NestList[IntegerReverse[#]+12&,1,60] (* Harvey P. Dale, Dec 16 2024 *)

Formula

After 2 steps enters a cycle of length 15.

A119454 Start with 34 and repeatedly reverse the digits and add 16 to get the next term.

Original entry on oeis.org

34, 59, 111, 127, 737, 753, 373, 389, 999, 1015, 5117, 7131, 1333, 3347, 7449, 9463, 3665, 5679, 9781, 1895, 5997, 8011, 1124, 4227, 7240, 443, 360, 79, 113, 327, 739, 953, 375, 589, 1001, 1017, 7117, 7133, 3333, 3349, 9449, 9465, 5665, 5681, 1881, 1897, 7997, 8013, 3124, 4229, 9240, 445, 560, 81
Offset: 1

Views

Author

Klaus Brockhaus, May 20 2006

Keywords

Comments

Has period 54. A full period is shown.
There are infinitely many numbers that eventually reach this cycle (e.g. 8100). What is the smallest? - N. J. A. Sloane, May 21 2006
The smallest number that eventually reaches this cycle is 26 (cf. A119481). - Klaus Brockhaus, May 23 2006

Crossrefs

A007398 Add 7, then reverse digits.

Original entry on oeis.org

0, 7, 41, 84, 19, 62, 96, 301, 803, 18, 52, 95, 201, 802, 908, 519, 625, 236, 342, 943, 59, 66, 37, 44, 15, 22, 92, 99, 601, 806, 318, 523, 35, 24, 13, 2, 9, 61, 86, 39, 64, 17, 42, 94, 101, 801, 808, 518, 525, 235, 242, 942, 949, 659, 666, 376, 383, 93, 1, 8, 51, 85, 29, 63
Offset: 0

Views

Author

Keywords

Comments

From n = 1 the sequence is periodic with a period of 63. The Data without the initial 0 gives that period. - David A. Corneth, Aug 01 2018

References

  • J. Roberts, Lure of the Integers, Math. Assoc. America, 1992, p. 15.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Cf. A117828.

Programs

  • Maple
    rev:=proc(n) local nn, nnn: nn:=convert(n,base,10): add(nn[nops(nn)+1-j]*10^(j-1),j=1..nops(nn)) end: a[0]:=0: for n from 1 to 70 do a[n]:=rev(7+a[n-1]) od: seq(a[n],n=0..70); # Emeric Deutsch, Jul 28 2006
  • Mathematica
    NestList[FromDigits[Reverse[IntegerDigits[# + 7]]]&, 0, 60] (* Vincenzo Librandi, Aug 08 2017 *)
  • PARI
    first(n) =  my(res = vector(n)); res[1]=0; for(i = 2, n, res[i] = fromdigits(Vecrev(digits(res[i - 1] + 7)))); res \\ David A. Corneth, Aug 01 2018

Extensions

More terms from Emeric Deutsch, Jul 28 2006

A118090 Start with 1 and repeatedly reverse the digits and add 44 to get the next term.

Original entry on oeis.org

1, 45, 98, 133, 375, 617, 760, 111, 155, 595, 639, 980, 133, 375, 617, 760, 111, 155, 595, 639, 980, 133, 375, 617, 760, 111, 155, 595, 639, 980, 133, 375, 617, 760, 111, 155, 595, 639, 980, 133, 375, 617, 760, 111, 155, 595, 639, 980, 133, 375, 617, 760
Offset: 1

Views

Author

Luc Stevens (lms022(AT)yahoo.com), May 11 2006

Keywords

Comments

After 3 steps enters a cycle of length 9.

Crossrefs

Programs

  • Mathematica
    NestList[IntegerReverse[#]+44&,1,60] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Feb 03 2021 *)

A118150 Start with 1 and repeatedly reverse the digits and add 53 to get the next term.

Original entry on oeis.org

1, 54, 98, 142, 294, 545, 598, 948, 902, 262, 315, 566, 718, 870, 131, 184, 534, 488, 937, 792, 350, 106, 654, 509, 958, 912, 272, 325, 576, 728, 880, 141, 194, 544, 498, 947, 802, 261, 215, 565, 618, 869, 1021, 1254, 4574, 4807, 7137, 7370, 790, 150, 104
Offset: 1

Views

Author

Luc Stevens (lms022(AT)yahoo.com), May 14 2006

Keywords

Comments

After 49 steps enters a cycle of 54.

Crossrefs

Programs

  • Mathematica
    NestList[IntegerReverse[#]+53&,1,60] (* Harvey P. Dale, Sep 21 2023 *)

Extensions

Corrected by Harvey P. Dale, Apr 19 2014

A118155 Start with 1 and repeatedly reverse the digits and add 59 to get the next term.

Original entry on oeis.org

1, 60, 65, 115, 570, 134, 490, 153, 410, 73, 96, 128, 880, 147, 800, 67, 135, 590, 154, 510, 74, 106, 660, 125, 580, 144, 500, 64, 105, 560, 124, 480, 143, 400, 63, 95, 118, 870, 137, 790, 156, 710, 76, 126, 680, 145, 600, 65, 115, 570, 134, 490, 153, 410
Offset: 1

Views

Author

Luc Stevens (lms022(AT)yahoo.com), May 14 2006

Keywords

Comments

After 2 steps enters a cycle of 45.

Crossrefs

Programs

  • Mathematica
    NestList[FromDigits[Reverse[IntegerDigits[#]]]+59&,1,80] (* Harvey P. Dale, Feb 25 2014 *)

Extensions

Corrected by Harvey P. Dale, Feb 25 2014

A118161 Start with 1 and repeatedly reverse the digits and add 55 to get the next term.

Original entry on oeis.org

1, 56, 120, 76, 122, 276, 727, 782, 342, 298, 947, 804, 463, 419, 969, 1024, 4256, 6579, 9811, 1244, 4476, 6799, 10031, 13056, 65086, 68111, 11241, 14266, 66296, 69321, 12451, 15476, 67506, 60631, 13661, 16686, 68716, 61841, 14871, 17896, 69926
Offset: 1

Views

Author

Luc Stevens (lms022(AT)yahoo.com), May 14 2006

Keywords

Comments

After 1371 steps enters a cycle of 36.

Crossrefs

Extensions

a(23) ff. corrected by Georg Fischer, Jul 17 2020

A118162 Start with 1 and repeatedly reverse the digits and add 60 to get the next term.

Original entry on oeis.org

1, 61, 76, 127, 781, 247, 802, 268, 922, 289, 1042, 2461, 1702, 2131, 1372, 2791, 2032, 2362, 2692, 3022, 2263, 3682, 2923, 3352, 2593, 4012, 2164, 4672, 2824, 4342, 2494, 5002, 2065, 5662, 2725, 5332, 2395, 5992, 3055, 5563, 3715, 5233, 3385, 5893, 4045
Offset: 1

Views

Author

Luc Stevens (lms022(AT)yahoo.com), May 14 2006

Keywords

Crossrefs

Programs

  • Mathematica
    NestList[IntegerReverse[#]+60&,1,50] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Aug 10 2017 *)

Formula

Never reaches a cycle (see A117816).
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