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 1-6 of 6 results.

A291639 Numbers k such that 0 is the smallest decimal digit of k^3.

Original entry on oeis.org

10, 16, 20, 22, 30, 34, 37, 40, 42, 43, 47, 48, 50, 52, 59, 60, 63, 67, 69, 70, 73, 74, 79, 80, 84, 86, 87, 89, 90, 93, 94, 99, 100, 101, 102, 103, 106, 107, 109, 110, 112, 115, 116, 117, 118, 120, 123, 124, 126, 127, 128, 130, 131, 134, 135, 138, 140, 141
Offset: 1

Views

Author

Colin Barker, Aug 28 2017

Keywords

Comments

The sequence is infinite. For example, A062397(i) is in the sequence for any i > 1, since A168575(i) contains the digit 0 for any i > 1. - Felix Fröhlich, Aug 28 2017
Also contains A008592, and has asymptotic density 1. - Robert Israel, Aug 29 2017

Examples

			16 is in the sequence because 16^3 = 4096, the smallest decimal digit of which is 0.
		

Crossrefs

Programs

  • Maple
    select(n -> min(convert(n^3,base,10))=0, [$1..1000]); # Robert Israel, Aug 29 2017
  • Mathematica
    Select[Range[150],DigitCount[#^3,10,0]>0&] (* Harvey P. Dale, Feb 03 2025 *)
  • PARI
    select(k->vecmin(digits(k^3))==0, vector(500, k, k))

A291642 Numbers k such that 3 is the smallest decimal digit of k^3.

Original entry on oeis.org

7, 15, 33, 46, 76, 77, 95, 96, 157, 167, 175, 179, 186, 197, 207, 213, 215, 326, 327, 332, 335, 353, 355, 379, 389, 427, 429, 437, 454, 457, 464, 714, 764, 775, 813, 816, 826, 859, 883, 922, 927, 942, 957, 1526, 1529, 1553, 1557, 1636, 1692, 1695, 1753, 1782
Offset: 1

Views

Author

Colin Barker, Aug 28 2017

Keywords

Examples

			33 is in the sequence because 33^3 = 35937, the smallest decimal digit of which is 3.
		

Crossrefs

Programs

  • Maple
    filter:= n -> min(convert(n^3,base,10))=3:
    select(filter, [$1..10000]); # Robert Israel, Aug 29 2017
  • Mathematica
    Select[Range[2000],Min[IntegerDigits[#^3]]==3&] (* Harvey P. Dale, Aug 31 2025 *)
  • PARI
    select(k->vecmin(digits(k^3))==3, vector(5000, k, k))

A291643 Numbers k such that 4 is the smallest decimal digit of k^3.

Original entry on oeis.org

4, 36, 204, 786, 842, 1682, 2114, 3795, 3859, 3863, 4429, 4459, 4559, 4635, 7644, 7913, 7914, 8183, 8286, 8372, 8744, 8864, 9144, 9263, 9599, 16592, 17094, 17863, 18923, 19035, 19563, 19829, 20364, 20635, 20776, 36264, 38183, 38389, 38432, 40186, 44216
Offset: 1

Views

Author

Colin Barker, Aug 28 2017

Keywords

Examples

			4 is in the sequence because 4^3 = 64, the smallest decimal digit of which is 4.
		

Crossrefs

Programs

  • Mathematica
    Select[Range[50000],Min[IntegerDigits[#^3]]==4&] (* Harvey P. Dale, Aug 13 2019 *)
  • PARI
    select(k->vecmin(digits(k^3))==4, vector(50000, k, k))

A291640 Numbers k such that 1 is the smallest decimal digit of k^3.

Original entry on oeis.org

1, 5, 6, 8, 11, 12, 13, 17, 21, 23, 24, 25, 26, 27, 28, 31, 39, 41, 44, 45, 49, 51, 53, 54, 55, 56, 57, 58, 61, 64, 68, 71, 75, 81, 82, 83, 85, 88, 91, 97, 98, 104, 105, 108, 111, 113, 114, 119, 121, 122, 125, 129, 136, 137, 139, 146, 147, 148, 151, 153, 156
Offset: 1

Views

Author

Colin Barker, Aug 28 2017

Keywords

Examples

			11 is in the sequence because 11^3 = 1331, the smallest decimal digit of which is 1.
		

Crossrefs

Programs

  • PARI
    select(k->vecmin(digits(k^3))==1, vector(500, k, k))

A291641 Numbers k such that 2 is the smallest decimal digit of k^3.

Original entry on oeis.org

3, 9, 14, 18, 29, 32, 35, 38, 62, 65, 66, 72, 78, 132, 133, 142, 144, 154, 155, 166, 177, 178, 188, 196, 198, 203, 282, 286, 288, 295, 296, 298, 305, 307, 322, 323, 328, 337, 357, 359, 362, 364, 375, 377, 382, 404, 412, 425, 444, 453, 463, 607, 609, 616, 632
Offset: 1

Views

Author

Colin Barker, Aug 28 2017

Keywords

Examples

			38 is in the sequence because 38^3 = 54872, the smallest decimal digit of which is 2.
		

Crossrefs

Programs

  • Mathematica
    Select[Range[700],Min[IntegerDigits[#^3]]==2&] (* Harvey P. Dale, Feb 23 2023 *)
  • PARI
    select(k->vecmin(digits(k^3))==2, vector(1000, k, k))

A333206 a(n) is the least decimal digit of n^3.

Original entry on oeis.org

0, 1, 8, 2, 4, 1, 1, 3, 1, 2, 0, 1, 1, 1, 2, 3, 0, 1, 2, 5, 0, 1, 0, 1, 1, 1, 1, 1, 1, 2, 0, 1, 2, 3, 0, 2, 4, 0, 2, 1, 0, 1, 0, 0, 1, 1, 3, 0, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 2, 0, 1, 2, 2, 0, 1, 0, 0, 1, 2, 0, 0, 1, 3, 3, 2, 0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 6, 0, 0, 3, 3, 1, 1
Offset: 0

Views

Author

Robert Israel, Mar 12 2020

Keywords

Comments

Dean Hickerson found an infinite sequence of n such that a(n) > 0 (see Guy, sec F24). Are there infinitely many such that a(n) > 1? If not, what is the greatest n with a(n)=k for each k > 1?
Heuristically, we should expect on the order of ((10-m)^3/100)^d terms n with d digits and a(n) >= m. Since 5^3/100 > 1 > 4^3/100 we should expect infinitely many terms with a(n) >= 5 but only finitely many terms with a(n) >= 6. See A291644 for a(n) = 5. There are only two n <= 10^6 with a(n) >= 6, namely a(2) = 8 and a(92) = 6.

Examples

			The least digit of 6^3=216 is 1, so a(6)=1.
		

References

  • R. Guy, Unsolved Problems in Number Theory (Third edition), Springer 2004.

Crossrefs

Programs

  • Maple
    seq(min(convert(n^3,base,10)),n=0..200);

Formula

a(n) = A054054(n^3).
Showing 1-6 of 6 results.