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 1-8 of 8 results.

A278937 Numbers k such that 3 is the largest decimal digit of k^3.

Original entry on oeis.org

11, 101, 110, 1001, 1010, 1100, 10001, 10010, 10100, 11000, 100001, 100010, 100100, 101000, 110000, 684917, 1000001, 1000010, 1000100, 1001000, 1010000, 1100000, 6849170, 10000001, 10000010, 10000100, 10001000, 10010000, 10100000, 11000000
Offset: 1

Views

Author

Colin Barker, Dec 02 2016

Keywords

Comments

A038444 is a subsequence. Are there an infinite number of terms not in A038444 that are not a multiple of 10? - Chai Wah Wu, Dec 02 2016
Conjecture: sequence is equal to A038444 plus terms of the form 684917*10^k for k >= 0. - Chai Wah Wu, Sep 02 2017
Conjecture is true up to 4.8*10^18. - Giovanni Resta, Sep 03 2017

Examples

			684917 is in the sequence because 684917^3 = 321302302131323213.
		

Crossrefs

Cf. A000578 (the cubes: n^3), A038444, A277960 (analog for squares), A278936 (cubes of the terms: a(n)^3).
Cf. A031997 (the odd terms).

Programs

  • Magma
    [n: n in [1..2*10^7] | Max(Intseq(n^3)) eq 3]; // Vincenzo Librandi, Dec 03 2016
  • Mathematica
    Select[Range[11 10^6],Max[IntegerDigits[#^3]]==3&] (* Harvey P. Dale, Feb 11 2025 *)
  • PARI
    select(n->vecmax(digits(n^3))==3, vector(1000000, n, n))
    

Formula

a(n)^3 = A278936(n).

A294663 Cubes whose largest digit is 4.

Original entry on oeis.org

343, 314432, 343000, 34012224, 314432000, 343000000, 34012224000, 314432000000, 343000000000, 442102433032, 30304210142233, 34012224000000, 143121324002112, 314432000000000, 333014302331144, 343000000000000, 442102433032000, 30304210142233000, 34012224000000000
Offset: 1

Views

Author

M. F. Hasler, Nov 12 2017

Keywords

Comments

For any term a(n), all numbers of the form a(n)*10^3k, k >= 0, are in this sequence. Primitive terms, i.e., not of this form (or equivalently: without trailing '0'), are 343, 314432, 34012224, 442102433032, 30304210142233, 143121324002112, 333014302331144, ...

Examples

			343 is in the sequence because it is a cube, 343 = 7^3, and its largest digit is 4.
		

Crossrefs

Cf. A294664 (the corresponding cubic roots).
Cf. A277948 = A277961^2 (analog for squares).
Cf. A278936, A295025, A295021, ..., A295024 (analog for digits 3, 5, 6, ..., 9).
Cf. A000578 (the cubes).

Programs

  • PARI
    for(n=1,2e8, vecmax(digits(n^3))==4&&print1(n^3,","))

Formula

a(n) = A294664(n)^3.

A295025 Cubes whose largest digit is 5.

Original entry on oeis.org

125, 512, 125000, 405224, 512000, 531441, 1225043, 5000211, 5545233, 13312053, 43243551, 54010152, 102503232, 115501303, 125000000, 221445125, 320013504, 400315553, 405224000, 512000000, 531441000, 1204550144, 1225043000, 2053225511, 2253243231, 2543302125
Offset: 1

Views

Author

M. F. Hasler, Nov 12 2017

Keywords

Comments

For any term a(n), all numbers of the form a(n)*10^3k, k >= 0, are in this sequence. Primitive terms, i.e., not of this form (or equivalently: without trailing '0'), are 125, 512, 405224, 531441, 1225043, 5000211, 5545233, 13312053, 43243551, ...

Examples

			512 is in the sequence because it is a cube, 512 = 8^3, and its largest digit is 5.
		

Crossrefs

Cf. A294665 (the corresponding cube roots), A278936 and A294663 (same for digit 3 and 4).
Cf. A000578 (the cubes).

Programs

  • PARI
    for(n=1,2e8, vecmax(digits(n^3))==5&&print1(n^3,","))
    
  • Python
    def ok(cube): return max(str(cube)) == "5"
    print([c for c in (i**3 for i in range(1370)) if ok(c)]) # Michael S. Branicky, Dec 05 2021

Formula

a(n) = A294665(n)^3.

A295021 Cubes whose largest digit is 6.

Original entry on oeis.org

64, 216, 15625, 46656, 50653, 64000, 132651, 216000, 262144, 456533, 614125, 636056, 1601613, 1643032, 2406104, 2515456, 3112136, 3652264, 6331625, 10360232, 13144256, 15625000, 41063625, 46656000, 50653000, 52313624, 55306341, 56623104, 64000000, 66430125, 100544625
Offset: 1

Views

Author

M. F. Hasler, Nov 13 2017

Keywords

Comments

For any term a(n), all numbers of the form a(n)*10^3k, k >= 0, are in this sequence. We could call "primitive" the terms not of this form, i.e., those without trailing '0'.

Examples

			64 is in the sequence because it is a cube, 64 = 4^3, and its largest digit is 6.
		

Crossrefs

Cf. A294996 (the corresponding cube roots); A278936, A294663, A295025, A295022, A295023, A295024 (same for digit 3 .. 9); A295016 (same for squares).
Cf. A000578 (the cubes).

Programs

  • Mathematica
    Select[Range[500]^3,Max[IntegerDigits[#]]==6&] (* Harvey P. Dale, Jun 21 2022 *)
  • PARI
    for(n=1,500, vecmax(digits(n^3))==6 &&print1(n^3,","))

Formula

a(n) = A294996(n)^3.

A295022 Cubes whose largest digit is 7.

Original entry on oeis.org

27, 2744, 3375, 12167, 17576, 27000, 157464, 166375, 175616, 250047, 274625, 300763, 474552, 753571, 1157625, 1367631, 1771561, 2000376, 2352637, 2460375, 2571353, 2744000, 3176523, 3375000, 4330747, 4657463, 4741632, 5177717, 5451776, 6644672, 7645373, 11543176, 12167000
Offset: 1

Views

Author

M. F. Hasler, Nov 13 2017

Keywords

Comments

For any term a(n), all numbers of the form a(n)*10^3k, k >= 0, are in this sequence. We could call "primitive" the terms not of this form, i.e., those without trailing '0'.

Examples

			27 is in the sequence because it is a cube, 27 = 3^3, and its largest digit is 7.
		

Crossrefs

Cf. A294997 (the corresponding cube roots); A278936, A294663, A295025, A295021, A295023, A295024 (same for digit 3 .. 9); A295017 (same for squares).
Cf. A000578 (the cubes).

Programs

  • PARI
    for(n=1,250, vecmax(digits(n^3))==7 &&print1(n^3,","))

Formula

a(n) = A294997(n)^3.

A295024 Cubes whose largest digit is 9.

Original entry on oeis.org

729, 2197, 4096, 4913, 6859, 9261, 19683, 21952, 24389, 29791, 35937, 39304, 59319, 68921, 79507, 91125, 97336, 110592, 117649, 185193, 195112, 205379, 226981, 287496, 328509, 357911, 389017, 438976, 493039, 592704, 704969, 729000, 912673, 941192, 970299, 1092727, 1191016
Offset: 1

Views

Author

M. F. Hasler, Nov 13 2017

Keywords

Comments

For any term a(n), all numbers of the form a(n)*10^3k, k >= 0, are in this sequence. We could call "primitive" the terms not of this form, i.e., those without trailing '0'.

Examples

			2197 is in the sequence because it is a cube, 2197 = 13^3, and its largest digit is 9.
		

Crossrefs

Cf. A294999 (the corresponding cube roots), A278936, A294663, A295025, A295021, A295022, A295023 (same for digit 3 .. 8), A295019 (same for squares).
Cf. A000578 (the cubes).

Programs

  • PARI
    for(n=1,150, vecmax(digits(n^3))==8 &&print1(n^3,","))

Formula

a(n) = A294999(n)^3.

A295023 Cubes whose largest digit is 8.

Original entry on oeis.org

8, 1728, 5832, 8000, 10648, 13824, 32768, 42875, 54872, 74088, 85184, 103823, 140608, 148877, 238328, 373248, 421875, 551368, 571787, 658503, 681472, 778688, 804357, 830584, 857375, 884736, 1061208, 1124864, 1481544, 1520875, 1728000, 1815848, 1860867, 2048383, 2628072, 2803221
Offset: 1

Views

Author

M. F. Hasler, Nov 13 2017

Keywords

Comments

For any term a(n), all numbers of the form a(n)*10^3k, k >= 0, are in this sequence. We could call "primitive" the terms not of this form, i.e., those without trailing '0'.

Examples

			8 is in the sequence because it is a cube, 8 = 2^3, and its largest digit is 8.
		

Crossrefs

Cf. A294998 (the corresponding cube roots), A278936, A294663, A295025, A295021, A295022, A295024 (same for digit 3 .. 9), A295018 (same for squares).
Cf. A000578 (the cubes).

Programs

  • PARI
    for(n=1,200, vecmax(digits(n^3))==8 &&print1(n^3,","))

Formula

a(n) = A294998(n)^3.

A031997 Odd numbers which when cubed give number composed just of the digits 0, 1, 2, 3.

Original entry on oeis.org

1, 11, 101, 1001, 10001, 100001, 684917, 1000001, 10000001, 100000001, 1000000001, 10000000001, 100000000001, 1000000000001, 10000000000001, 100000000000001, 1000000000000001, 10000000000000001, 100000000000000001, 1000000000000000001
Offset: 1

Views

Author

Robert G. Wilson v, Jun 23 2001

Keywords

Comments

Note that 684917 (whose cube is 321302302131323213) so far is the only entry not of the form 10^x + 1.

Crossrefs

Programs

  • Mathematica
    Do[ If[ Union[ IntegerDigits[ n^3 ] ] [ [ -1 ] ] < 4, Print[ n ] ], {n, 1, 10^9, 2} ] (* corrected by Friedjof Tellkamp, Apr 24 2025 *)
    (* faster code *)
    DigitsLEQ3[n_] := And @@ (LessEqual[#, 3] & /@ IntegerDigits[n])
    Arr = {1, 7}; For[i = 1, i < 10, i++, Arr = Flatten[Table[Select[Arr + 10^i j, DigitsLEQ3[Mod[#^3, 10^(i+1)]] &], {j, 0, 9}]]];
    Select[Arr, DigitsLEQ3[#^3] &] (* Friedjof Tellkamp, Apr 25 2025 *)
  • Python
    A031997_list = [n for n in range(1,10**6,2) if max(str(n**3)) <= '3'] # Chai Wah Wu, Feb 23 2016

Extensions

Term 0 removed and a(12)-a(17) added by Chai Wah Wu, Feb 25 2016
a(18)-a(20) from Giovanni Resta, Mar 14 2020
Showing 1-8 of 8 results.