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.

Previous Showing 11-18 of 18 results.

A033899 Sort then Add, a(1)=17.

Original entry on oeis.org

17, 34, 68, 136, 272, 499, 998, 1897, 3686, 7354, 10811, 11929, 23228, 45466, 90032, 90271, 91550, 93109, 94508, 99097, 107096, 108775, 124553, 248008, 250496, 275065, 300632, 302968, 326657, 562324, 785780, 843568, 1189256, 2314945, 3549404
Offset: 1

Views

Author

Keywords

Crossrefs

Cf. A033860.

Programs

  • Maple
    A033899 := proc(n)
        option remember ;
        if n =1 then
            17;
        else
            A070196(procname(n-1)) ;
        end if;
    end proc:
    seq(A033899(n),n=1..100) ; # R. J. Mathar, Feb 03 2025
  • Mathematica
    NestList[FromDigits[Sort[IntegerDigits[#]]]+#&, 17,40] (* Harvey P. Dale, Apr 07 2018 *)

A033900 Sort then Add, a(1)=19.

Original entry on oeis.org

19, 38, 76, 143, 277, 554, 1009, 1028, 1156, 2312, 3535, 6890, 7579, 13358, 26716, 39383, 72772, 95549, 141148, 252596, 478165, 623843, 857311, 970889, 1049788, 1197677, 2365456, 4711022, 4823269, 7057958, 7615747, 9072524, 9297103, 9420902
Offset: 1

Views

Author

Keywords

Crossrefs

Cf. A033860.

Programs

  • Maple
    A033900 := proc(n)
        option remember ;
        if n =1 then
            19;
        else
            A070196(procname(n-1)) ;
        end if;
    end proc:
    seq(A033900(n),n=1..100) ; # R. J. Mathar, Feb 03 2025
  • Mathematica
    NestList[#+FromDigits[Sort[IntegerDigits[#]]]&,19,40] (* Harvey P. Dale, Sep 02 2022 *)

A033901 Sort then Add, a(1)=21.

Original entry on oeis.org

21, 33, 66, 132, 255, 510, 525, 780, 858, 1446, 2892, 5181, 6339, 9708, 10497, 11976, 23655, 47211, 58458, 104046, 105492, 117951, 229530, 251889, 377778, 755556, 1311123, 2422356, 4645812, 5890380, 5926269, 8182968, 9451857, 10907646
Offset: 1

Views

Author

Keywords

Crossrefs

Cf. A033860.

Programs

  • Maple
    A033901 := proc(n)
        option remember ;
        if n =1 then
            21;
        else
            A070196(procname(n-1)) ;
        end if;
    end proc:
    seq(A033901(n),n=1..100) ; # R. J. Mathar, Feb 03 2025
  • Mathematica
    NestList[FromDigits[Sort[IntegerDigits[#]]]+#&,21,40] (* Harvey P. Dale, Feb 23 2023 *)

Formula

a(n)=A033898(n+1), n>1. [From R. J. Mathar, Oct 22 2008]

A033903 Sort then Add, a(1)=27.

Original entry on oeis.org

27, 54, 99, 198, 387, 765, 1332, 2565, 5121, 6246, 8712, 9990, 10989, 12888, 25776, 51453, 64908, 69597, 126396, 250065, 252621, 374877, 722655, 948222, 1170711, 1281888, 2410776, 2535453, 4870008, 4874796, 9342585, 11688174, 22834962
Offset: 1

Views

Author

Keywords

Crossrefs

Cf. A033860.

Programs

  • Maple
    A033903 := proc(n)
        option remember ;
        if n =1 then
            27;
        else
            A070196(procname(n-1)) ;
        end if;
    end proc:
    seq(A033903(n),n=1..100) ; # R. J. Mathar, Feb 03 2025
  • Mathematica
    NestList[#+FromDigits[Sort[IntegerDigits[#]]]&,27,40] (* Harvey P. Dale, May 21 2023 *)

A033904 Sort then Add, a(1)=29.

Original entry on oeis.org

29, 58, 116, 232, 455, 910, 929, 1228, 2456, 4912, 6161, 7327, 9704, 10183, 11321, 22444, 44888, 89776, 157565, 313132, 425465, 670021, 671288, 798076, 865865, 1422553, 2646008, 2670676, 2937353, 5270932, 5494511, 6639070, 6675749
Offset: 1

Views

Author

Keywords

Crossrefs

Cf. A033860.

Programs

A033906 Sort then Add, a(1)=20.

Original entry on oeis.org

20, 22, 44, 88, 176, 343, 677, 1354, 2699, 5398, 8987, 16876, 33554, 67009, 67688, 134476, 268943, 503632, 526988, 783877, 1161665, 2277331, 3500708, 3504286, 3738854, 7084642, 7329320, 7552699, 10109498, 10224397, 11447876, 22894654
Offset: 1

Views

Author

Keywords

Crossrefs

Cf. A033860.

Programs

  • Maple
    A033906 := proc(n)
        option remember ;
        if n =1 then
            20;
        else
            A070196(procname(n-1)) ;
        end if;
    end proc:
    seq(A033906(n),n=1..100) ; # R. J. Mathar, Feb 03 2025
  • Mathematica
    NestList[#+FromDigits[Sort[IntegerDigits[#]]]&,20,40] (* Harvey P. Dale, Oct 28 2017 *)

Formula

a(n)=A033905(n-1), n>2. [From R. J. Mathar, Oct 22 2008]

A033907 Sort then Add, a(1)=32.

Original entry on oeis.org

32, 55, 110, 121, 233, 466, 932, 1171, 2288, 4576, 9143, 10492, 11741, 22888, 45776, 91453, 104912, 116161, 227327, 449704, 494183, 628672, 855350, 890908, 899807, 978706, 1046495, 1191064, 1302533, 1425868, 2671556, 3927223, 6150602, 6163168
Offset: 1

Views

Author

Keywords

Crossrefs

Cf. A033860.

Programs

Formula

a(n)=A033902(n+1), n>1. - R. J. Mathar, Oct 22 2008

A371478 Numbers k for which k swaps are needed to bubble-sort the US English number name of k.

Original entry on oeis.org

2, 17, 21, 25
Offset: 1

Views

Author

Eric Angelini and Nicolas Graner, Mar 25 2024

Keywords

Comments

No swaps involve hyphens or spaces.
Only four such numbers < 100 have this property: are there more?
In French, only three such numbers are known: 1, 14, 23.
For number names up to one million, the number of swaps does not exceed 712. - Hans Havermann, Mar 25 2024
There are no more terms. Computationally, there are none < 10^9. If the name of n has k letters, a(n) <= k*(k-1)/2 from the properties of bubble sort. Also, if 1000^(e-1) <= n < 1000^e, then k <= 41*e, where the loose upper bound comes from "threehundredseventythree" and "quattuordecillion" considering all terms up to 10^66 using English names of large numbers (see Wikipedia link). Thus, a(n) <= 820*e^2 <= 1000^(e-1) for e >= 3. Similar bounds can be derived for extended naming schemes. - Michael S. Branicky, Mar 26 2024

Examples

			2 is a term since "two" requires 2 swaps of adjacent letters to sort into ascending alphabetical order: TWO -> TOW -> OTW.
		

Crossrefs

Previous Showing 11-18 of 18 results.