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 1-3 of 3 results.

A154874 Numbers k such that k^3 contains every digit exactly twice.

Original entry on oeis.org

2158479, 2190762, 2205528, 2219322, 2301615, 2330397, 2336268, 2345811, 2358828, 2359026, 2367609, 2388534, 2389119, 2389638, 2397132, 2428986, 2504736, 2524974, 2536152, 2583258, 2590125, 2607222, 2620827, 2622012, 2647866, 2649369, 2658636, 2671593
Offset: 1

Views

Author

Zhining Yang, Jan 16 2009

Keywords

Comments

This sequence has 138 terms.

Examples

			2358828^3 = 13124683009764879552, which contains each digit 0..9 exactly twice.
		

Crossrefs

Programs

  • Maple
    lim:=floor((10^20)^(1/3)): for j from ceil((10^19)^(1/3)) to lim do d:=convert(j^3,base,10): doubdig:=true: for k from 0 to 9 do if(numboccur(d,k)<>2)then doubdig:=false:break: fi: od: if(doubdig)then print(j); fi: od: # Nathaniel Johnston, May 28 2011
  • Mathematica
    With[{cmin=Ceiling[Surd[10^19,3]],cmax=Floor[Surd[10^20,3]]},Select[ Range[ cmin, cmax], Union[ DigitCount[#^3]]=={2}&]] (* Harvey P. Dale, Nov 17 2018 *)

A154875 Numbers k such that k^4 contains every digit exactly 3 times.

Original entry on oeis.org

17824719, 17940018, 18027474, 18197931, 18326025, 18798396, 18915888, 18929424, 19027455, 19149462, 19180275, 19196064, 19235673, 19311297, 19322913, 19324275, 19328322, 19455918, 19522575, 19757886, 19793664
Offset: 1

Views

Author

Zhining Yang, Jan 16 2009

Keywords

Examples

			22807116 ^ 4 = 270571148920443982076865351936, which contains exactly 3 times of each digit 0-9.
		

Crossrefs

Programs

  • Mathematica
    Select[Range[17824000,31608000],Union[Tally[IntegerDigits[#^4]][[All,2]]]=={3}&] (* Harvey P. Dale, Dec 24 2016 *)
  • PARI
    is(n) = my(v=vector(10), d=digits(n^4)); if(#d!=30,return(0)); for(i=1, #d, v[d[i]+1]++; if(v[d[i]+1] > 3, return(0))); 1 \\ David A. Corneth, Aug 19 2025

A154876 10-digit numbers n such that n^16 contains every digit exactly 16 times.

Original entry on oeis.org

8691229761, 8776040742, 8800099059, 8812428855, 8813522223, 8815323864, 8823675177, 8886940968, 9239038038, 9324907263, 9480130515, 9500938647, 9643844169, 9801034758, 9857840688, 9872688021, 9962545842, 9970902252
Offset: 1

Views

Author

Zhining Yang, Jan 16 2009

Keywords

Comments

The search program was provided by wuxinren(http://bbs.emath.ac.cn/space-uid-80.html): http://bbs.emath.ac.cn/attachment.php?aid=697&k=37ef434325a887e1a6f268d69d06192a&t=1232126232

Examples

			8691229761^16=1059984945135973085116625441940958734567890938937942910046410302827750560860737374626331724228885721853160790705924439371252226476405367618058329962361885148161 means that 16th power of 8691229761 has all digit(0-9) each for 16 times exactly
		

Crossrefs

Showing 1-3 of 3 results.