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 1-7 of 7 results.

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.

A294664 Numbers n such that the largest digit of n^3 is 4.

Original entry on oeis.org

7, 68, 70, 324, 680, 700, 3240, 6800, 7000, 7618, 31177, 32400, 52308, 68000, 69314, 70000, 76180, 311770, 324000, 353068, 523080, 680000, 693140, 700000, 756658, 761800, 1039247, 2715974, 2732441, 3117700, 3240000, 3511617, 3530680, 4689368, 5230800, 6800000, 6931400, 7000000
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^k, k >= 0, are in this sequence. Primitive terms, i.e., not of this form (or equivalently: without trailing '0'), are 7, 68, 324, 7618, 31177, 52308, 69314, 353068, 756658, 1039247, 2715974, 2732441, 3511617, 4689368, 7571814, 12811968, 15904541, ...
All terms have last nonzero digit 1, 4, 7 or 8 and leading digit <= 7. - Robert Israel, Nov 13 2017
The number formed by the first m digits of a term is always less than c*10^m with c = (4/9)^(1/3) = .7631428283688879... - M. F. Hasler, Nov 13 2017

Examples

			7 is in the sequence because the largest digit of 7^3 = 343 is 4.
		

Crossrefs

Cf. A294663 (the corresponding cubes), A278937, A294665, A294996 - A294999 (analog for digits 3, 5, 6 - 9); A277961 (analog for squares).
Cf. A000578 (the cubes).

Programs

  • Maple
    select(n -> max(convert(n^3,base,10))=4, [$1..10^6]); # Robert Israel, Nov 13 2017
  • PARI
    for(n=1,2e8, vecmax(digits(n^3))==4&&print1(n","))

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.

A294662 Least k > a(n-1) such that k^3 has no digit in common with a(n-1) and a(n+1), a(0)=0.

Original entry on oeis.org

0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 29, 55, 88, 90, 111, 200, 211, 400, 518, 654, 888, 889, 1111, 2825, 3131, 4244, 11111, 28222, 31535, 42449, 53355, 90000, 111181, 590000, 618181, 900000, 1111115, 9000000, 11111115, 60660090, 114144155
Offset: 0

Views

Author

M. F. Hasler, Nov 09 2017

Keywords

Comments

This is the sequence which corresponds to the original definition of A030290, before it was corrected to reproduce the data (and the intended meaning).

Examples

			a(3) cannot be 3 because 3^3 = 27 would have the digit '2' in common with a(2) = 2, therefore a(3) = 4, which does not violate this condition.
After a(9) = 10, none of the numbers { 11, ..., 19 } can follow, because they have the digit '1' in common with a(9)^3 = 1000. Numbers { 20, ..., 28 } are excluded because their cube would have a digit '0' or '1' in common with a(9). Therefore, a(10) = 29 which hasn't a digit in common with a(9)^3, nor has 29^3 = 24389 a digit in common with a(9).
a(38) = 11111115 with 11111115^3 = 1371743552812575445875 using all digits except for 0, 6 and 9. So a(39) = 60660090 is possible, with a(39)^3 = 223207688999086038729000 having all digits except for 1, 4 and 5.
		

Crossrefs

Programs

  • PARI
    nxt(a,L=oo,D(a)=Set(digits(a)),S=D(a),T=D(a^3))={for(k=a+1,L, #setintersect(D(k),T)||#setintersect(D(k^3),S)||return(k))}
    A294662=List(); a=0; until(!a=nxt(a,1e7),write("/tmp/A294662.txt",#A294662," ",a);listput(A294662,a))
Showing 1-7 of 7 results.