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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A063060 'Reverse and Add!' trajectory of 10553.

Original entry on oeis.org

10553, 46054, 91118, 172237, 904508, 1709917, 8908988, 17807086, 85877957, 161855815, 680413976, 1359728062, 3968007593, 7925016286, 14751121583, 53263237324, 95636473559, 191173937218, 1003913308409, 10051946501410
Offset: 0

Views

Author

Klaus Brockhaus, Jul 07 2001

Keywords

Examples

			a(1) = 10553 + 35501 = 46054.
		

Crossrefs

Programs

  • ARIBAS
    m := 10553; stop := 25; c := 0; rev := int_reverse(m); while m <> rev and c < stop do inc(c); write(m," "); m := m + rev; rev := int_reverse(m); end;
    
  • Haskell
    a063060 n = a063060_list !! n
    a063060_list = iterate a056964 10553 -- Reinhard Zumkeller, Sep 22 2011
  • Mathematica
    NestList[# + FromDigits[Reverse[IntegerDigits[#]]]&, 10553, 40] (* Vincenzo Librandi, May 03 2014 *)

Extensions

Updated b-file from Michael Lee, Apr 01 2012

A063063 'Reverse and Add!' trajectory of 10563.

Original entry on oeis.org

10563, 47064, 93138, 176277, 948948, 1798797, 9777768, 18455547, 93011028, 175022067, 935242638, 1771485177, 9487326948, 17983564797, 97730103768, 184460207547, 930162272028, 1750434533067, 9353788873638, 17717577747177
Offset: 0

Views

Author

Klaus Brockhaus, Jul 07 2001

Keywords

Examples

			a(1) = 10563 + 36501 = 47064.
		

Crossrefs

Programs

  • ARIBAS
    m := 10563; stop := 25; c := 0; rev := int_reverse(m); while m <> rev and c < stop do inc(c); write(m," "); m := m + rev; rev := int_reverse(m); end;
    
  • Haskell
    a063063 n = a063063_list !! n
    a063063_list = iterate a056964 10563 -- Reinhard Zumkeller, Sep 22 2011
  • Mathematica
    NestList[# + FromDigits[Reverse[IntegerDigits[#]]]&, 10563, 30] (* Vincenzo Librandi, May 03 2014 *)

A066054 'Reverse and Add!' trajectory of 10583.

Original entry on oeis.org

10583, 49084, 97178, 184357, 937838, 1776577, 9533348, 17966707, 88733678, 176367466, 841131137, 1572262285, 7394885036, 13700769973, 51697470704, 92404950319, 183710890748, 1030808908129, 10248906988430, 13737867972631
Offset: 0

Views

Author

Klaus Brockhaus, Nov 30 2001

Keywords

Examples

			a(1) = 10583 + 38501 = 49084.
		

Crossrefs

Programs

  • ARIBAS
    : m := 10583; stop := 20; c := 0; rev := int_reverse(m); while m <> rev and c < stop do inc(c); write(m," "); m := m + rev; rev := int_reverse(m); end;
    
  • Haskell
    a066054 n = a066054_list !! n
    a066054_list = iterate a056964 10583 -- Reinhard Zumkeller, Sep 22 2011
  • Mathematica
    NestList[# + FromDigits[Reverse[IntegerDigits[#]]]&,  10583, 40] (* Vincenzo Librandi, May 03 2014 *)
  • PARI
    Rev(x)= { local(d, r=0); while (x>0, d=x%10; x\=10; r=r*10 + d); return(r) } { a=10583; for (n = 0, 150, if (n, a+=Rev(a)); write("b066054.txt", n, " ", a) ) } \\ Harry J. Smith, Nov 08 2009
    

A348570 Positive integers which apparently never result in a palindrome under repeated applications of the function f(x) = x + (x with digits in Zeckendorf representation reversed). Zeckendorf representation analog of Lychrel numbers.

Original entry on oeis.org

59, 61, 69, 75, 77, 100, 105, 113, 115, 122, 128, 130, 131, 135, 136, 140, 142, 143, 148, 151, 153, 160, 162, 163, 166, 172, 177, 180, 183, 188, 191, 192, 196, 198, 200, 209, 210, 212, 215, 222, 223, 229, 230, 231, 237, 240, 249, 250, 257, 258, 263, 264, 266
Offset: 1

Views

Author

A.H.M. Smeets, Oct 23 2021

Keywords

Comments

Zeckendorf representation version of A023108 (base 10).
For the Zeckendorf representation of numbers see A014417.
For palindromic numbers in Zeckendorf representation see A094202.
The "Reverse and Add!" operation (A349239) applied in Zeckendorf representation seems to behave similarly to the "Reverse and Add!" operation applied in any fixed-base representation. The first 53 terms are however obtained after performing 10^4 "Reverse and Add!" steps (see Python program).
For records and record-setting values in the number of "Reverse and Add!" steps see A348572 and A348571 respectively.
Do any of these numbers have a trajectory in which the Lychrel property can be proved (like 22 in base 2 as in A061561)?
Iteration steps are given by n := n+A349238(n), or n := A349239(n).
Closure of reverse operation is given by: Let Z be the regular expression for numbers in Zeckendorf representation, Z = 0|(100*)*10*, and L(Z) its corresponding regular language. Then for s in L(Z), the reversal of s is in L(0*)L(Z).
Let h be the homomorphism from Zeckendorf representation to a conventional radix representation, then addition in Zeckendorf representation, +_Z, is given by z1 +_Z z2 = h^(-1)(h(z1) + h(z2)). A direct method for addition in Zeckendorf representation is given by Ahlbach et al.

Crossrefs

Lychrel numbers in fixed bases: A066059 (base 2), A077404 (base 3), A075420 (base 4), A023108 (base 10).

Programs

  • Python
    # Using functions NumToFib and RevFibToNum from A349238.
    n, a = 0, 0
    while n < 53:
        a += 1
        aa, sa = a, NumToFib(a)
        ar, s = RevFibToNum(sa), 0
        while aa != ar and s < 10000:
            s, aa = s+1, aa+ar
            sa = NumToFib(aa)
            ar = RevFibToNum(sa)
        if aa != ar:
            n += 1
            print(a, end = ", ")

A030547 Number of terms (including the initial term) needed to reach a palindrome when the Reverse Then Add! map (x -> x + (x-with-digits-reversed)) is repeatedly applied to n, or -1 if a palindrome is never reached.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 1, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 1, 2, 2, 2, 3, 2, 3, 2, 2, 2, 2, 1, 2, 3, 2, 3, 3, 2, 2, 2, 2, 2, 1, 2, 3, 3, 4, 2, 2, 2, 2, 3, 2, 1, 3, 4, 5, 2, 2, 2, 3, 2, 3, 3, 1, 5, 7, 2, 2, 3, 2, 3, 3, 4, 5, 1, 25, 2, 3, 2, 3, 3, 4, 5, 7, 25
Offset: 1

Views

Author

Keywords

Comments

It is conjectured that a(196) is the smallest term equal to -1. See A023108.

References

  • Daniel Lignon, Dictionnaire de (presque) tous les nombres entiers, Ellipses, Paris, 2012, 702 pages. See Entry 196.

Crossrefs

Cf. A006960, A023108, A063018, etc.
Equals A033665(n) + 1.

Programs

  • Mathematica
    Table[Length@
      NestWhileList[# + IntegerReverse[#] &, n, ! PalindromeQ[#]  &], {n, 98}] (* Robert Price, Oct 18 2019 *)

Extensions

Edited by N. J. A. Sloane, May 09 2015

A063052 Integers n > 879 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 879.

Original entry on oeis.org

978, 1497, 1587, 1677, 1767, 1857, 1947, 2496, 2586, 2676, 2766, 2856, 2946, 3495, 3585, 3675, 3765, 3855, 3945, 4494, 4584, 4674, 4764, 4854, 4944, 5493, 5583, 5673, 5763, 5853, 5943, 6492, 6582, 6672, 6762, 6852, 6942, 7491, 7581, 7671, 7761, 7851
Offset: 1

Views

Author

Klaus Brockhaus, Jul 07 2001

Keywords

Comments

Subsequence of A023108.

Examples

			The trajectory of 1497 reaches 9438 in one step and 9438 is a term in the trajectory of 879, so 1497 belongs to the present sequence. The corresponding term in A063053, giving the number of steps, accordingly is 1.
		

Crossrefs

Extensions

Offset corrected by Sean A. Irvine, Apr 17 2023

A063055 Integers n > 1997 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 1997.

Original entry on oeis.org

2996, 3995, 5993, 6992, 7991, 8089, 8179, 8269, 8359, 8449, 8539, 8629, 8719, 8809, 8899, 8989, 8990, 9088, 9178, 9268, 9358, 9448, 9538, 9628, 9718, 9808, 9898, 9988, 13397, 14387, 15377, 16367, 17357, 17897, 18347, 18887, 19337, 19877, 23396
Offset: 0

Views

Author

Klaus Brockhaus, Jul 07 2001

Keywords

Comments

Subsequence of A023108.

Examples

			The trajectory of 3995 reaches 9988 in one step and 9988 is a term in the trajectory of 1997, so 3995 belongs to the present sequence. The corresponding term in A063056, giving the number of steps, accordingly is 1.
		

Crossrefs

A063058 Integers n > 7059 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 7059.

Original entry on oeis.org

7149, 7239, 7329, 7419, 7509, 7599, 7689, 7779, 7869, 7959, 8058, 8148, 8238, 8328, 8418, 8508, 8598, 8688, 8868, 8958, 9057, 9147, 9237, 9327, 9417, 9507, 9597, 9687, 9777, 9867, 9957, 13596, 14586, 15576, 16566, 17292, 17556, 18096, 18282, 18546
Offset: 0

Views

Author

Klaus Brockhaus, Jul 07 2001

Keywords

Comments

Subsequence of A023108.

Examples

			The trajectory of 7239 reaches 16566 in one step and 16566 is a term in the trajectory of 7059, so 7239 belongs to the present sequence. The corresponding term in A063059, giving the number of steps, accordingly is 1.
		

Crossrefs

A063061 Integers n > 10553 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 10553.

Original entry on oeis.org

11543, 12097, 12533, 13087, 13523, 14077, 14513, 15067, 15503, 16057, 16597, 17047, 17587, 18037, 18577, 19027, 19567, 20552, 21542, 22096, 22532, 23086, 23522, 24076, 24512, 25066, 25502, 26056, 26596, 27046, 27586, 28036, 28576
Offset: 0

Views

Author

Klaus Brockhaus, Jul 07 2001

Keywords

Comments

Subsequence of A023108.

Examples

			The trajectory of 12097 reaches 91118 in one step and 91118 is a term in the trajectory of 10553, so 12097 belongs to the present sequence. The corresponding term in A063062, giving the number of steps, accordingly is 1.
		

Crossrefs

A063064 Integers n > 10563 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 10563.

Original entry on oeis.org

11553, 12543, 13533, 14097, 14523, 15087, 15513, 16077, 16503, 17067, 18057, 18597, 19047, 19587, 20562, 21552, 22542, 24096, 24522, 25086, 25512, 26076, 26502, 27066, 28056, 28596, 29046, 29586, 30561, 31551, 32541, 33531, 34095
Offset: 0

Views

Author

Klaus Brockhaus, Jul 07 2001

Keywords

Comments

Subsequence of A023108.

Examples

			The trajectory of 12543 reaches 47064 in one step and 47064 is a term in the trajectory of 10563, so 12543 belongs to the present sequence. The corresponding term in A063065, giving the number of steps, accordingly is 1.
		

Crossrefs

Previous Showing 31-40 of 70 results. Next