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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A065215 Numbers which need ten 'Reverse and Add' steps to reach a palindrome.

Original entry on oeis.org

829, 928, 9059, 9149, 9239, 9329, 9419, 9509, 9599, 9689, 9869, 9959, 10634, 10637, 10687, 10716, 10808, 10834, 10838, 10867, 10873, 10898, 10927, 10979, 11398, 11624, 11627, 11677, 11706, 11824, 11828, 11857, 11863, 11888, 11917, 11969, 12388, 12392, 12398, 12493
Offset: 1

Views

Author

Klaus Brockhaus, Oct 21 2001

Keywords

Comments

The number of steps starts at 0, so palindromes (cf. A002113) are excluded.
Numbers k such that A033665(k) = 10. - Andrew Howroyd, Dec 08 2024

Links

Crossrefs

Cf. A002113, A015991 (a different version), A033665, A065206.

Programs

  • Mathematica
    lenQ[n_]:= Length[NestWhileList[# + FromDigits[Reverse[IntegerDigits[#]]]&, n, #!= FromDigits[Reverse[IntegerDigits[#]]]&, 1, 11]] == 11; Select[Range[1000], lenQ] (* Vincenzo Librandi, Sep 24 2013 *)

A065216 Numbers which need eleven 'Reverse and Add' steps to reach a palindrome.

Original entry on oeis.org

167, 266, 365, 563, 662, 761, 860, 7069, 7159, 7249, 7339, 7429, 7519, 7609, 7699, 7789, 7879, 7969, 8068, 8158, 8248, 8428, 8518, 8608, 8698, 8788, 8878, 8968, 9039, 9067, 9129, 9157, 9219, 9247, 9309, 9337, 9399, 9427, 9489, 9517, 9579, 9607, 9697
Offset: 1

Views

Author

Klaus Brockhaus, Oct 21 2001

Keywords

Comments

The number of steps starts at 0, so palindromes (cf. A002113) are excluded.
Numbers k such that A033665(k) = 11. - Andrew Howroyd, Dec 08 2024

Links

Crossrefs

A002113, A015992, A033665, A065206.

Programs

  • Mathematica
    lenQ[n_]:= Length[NestWhileList[# + FromDigits[Reverse[IntegerDigits[#]]]&, n, #!= FromDigits[Reverse[IntegerDigits[#]]]&, 1, 12]] == 12; Select[Range[1000], lenQ] (* Vincenzo Librandi, Sep 24 2013 *)

Extensions

Offset changed from 0 to 1 by Harry J. Smith, Oct 14 2009

A065217 Numbers which need 12 'Reverse and Add' steps to reach a palindrome.

Original entry on oeis.org

2069, 2159, 2249, 2339, 2429, 2519, 2609, 2699, 2789, 2879, 2969, 3068, 3158, 3248, 3338, 3428, 3518, 3608, 3698, 3788, 3878, 3968, 4067, 4157, 4247, 4337, 4427, 4517, 4607, 4697, 4787, 4877, 4967, 5066, 5156, 5246, 5336, 5426, 5516, 5606, 5696, 5786
Offset: 1

Views

Author

Klaus Brockhaus, Oct 21 2001

Keywords

Comments

The number of steps starts at 0, so palindromes (cf. A002113) are excluded. This sequence coincides with the corresponding sequence not excluding palindromes (A015993) for the entries shown in the database. The first divergence occurs at 10901.
Numbers k such that A033665(k) = 12. - Andrew Howroyd, Dec 06 2024

Links

Crossrefs

Cf. A002113, A015993, A033665, A065206.

Programs

  • PARI
    isok(n,s=12)={for(k=0, s, my(r=fromdigits(Vecrev(digits(n)))); if(r==n, return(k==s)); n += r); 0} \\ Andrew Howroyd, Dec 06 2024

Extensions

Offset changed from 0 to 1 by Harry J. Smith, Oct 14 2009
Previous Showing 11-13 of 13 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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