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 1-10 of 12 results. Next

A018853 a(n)^4 is smallest fourth power beginning with n.

Original entry on oeis.org

0, 1, 4, 14, 8, 15, 5, 29, 3, 31, 10, 33, 6, 19, 11, 35, 2, 65, 37, 21, 12, 68, 69, 22, 7, 4, 72, 23, 13, 74, 132, 42, 134, 24, 43, 77, 138, 44, 14, 25, 8, 45, 144, 81, 46, 26, 147, 83, 47, 84, 15, 151, 85, 27, 86, 273, 154, 49, 276, 88, 157, 28, 5, 159, 283, 9, 286, 51, 91, 289, 29
Offset: 0

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Author

Keywords

Crossrefs

Cf. A018798 (a(n)^4).
Cf. A018851 (k=2), A018852 (k=3), this sequence (k=4), A018872 (k=5), A018874 (k=6), A018876 (k=7), A018878 (k=8), A018880 (k=9), A018882 (k=10).

Programs

  • PARI
    v=[]; k=1; while(#v<100, d=digits(k^4); D=digits(#v+1); if(#D<=#d, c=1; for(i=1, #D, if(D[i]!=d[i], c=0; break)); if(c, v=concat(v, k); k=0)); k++); v \\ Derek Orr, Aug 12 2015

Formula

a(n^4) = n for n >= 0. - Seiichi Manyama, Jan 30 2017

Extensions

Added initial 0. - Seiichi Manyama, Jan 30 2017

A018872 a(n)^5 is smallest fifth power beginning with n.

Original entry on oeis.org

0, 1, 3, 2, 21, 9, 23, 6, 61, 25, 4, 26, 66, 42, 17, 69, 7, 28, 18, 72, 29, 116, 47, 75, 3, 48, 192, 77, 31, 124, 79, 5, 2, 32, 51, 129, 205, 13, 52, 33, 21, 53, 212, 134, 85, 34, 136, 86, 137, 87, 55, 22, 35, 14, 352, 56, 224, 142, 226, 9, 36, 144, 91, 363, 23, 58, 146, 232, 147, 37
Offset: 0

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Author

Keywords

Crossrefs

Cf. A018851 (k=2), A018852 (k=3), A018853 (k=4), this sequence (k=5), A018874 (k=6), A018876 (k=7), A018878 (k=8), A018880 (k=9), A018882 (k=10).

Programs

  • PARI
    a(n) = my(k=0, ss=Str(n)); while(strsplit(Str(k^5), ss)[1] != "", k++); k; \\ Michel Marcus, Aug 19 2025

Formula

a(n^5) = n for n >= 0. - Seiichi Manyama, Jan 30 2017

Extensions

Added initial 0. - Seiichi Manyama, Jan 30 2017

A018874 a(n)^6 is smallest sixth power beginning with n.

Original entry on oeis.org

0, 1, 8, 18, 4, 9, 2, 3, 21, 46, 10, 7, 33, 49, 23, 5, 16, 11, 35, 24, 77, 36, 53, 115, 17, 37, 8, 55, 81, 12, 26, 121, 83, 263, 18, 39, 124, 85, 27, 271, 4, 127, 59, 87, 188, 189, 6, 19, 13, 89, 131, 61, 132, 9, 42, 133, 62, 134, 197, 29, 92, 292, 63, 43, 2, 201, 137, 202, 64, 138
Offset: 0

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Author

Keywords

Crossrefs

Cf. A018851 (k=2), A018852 (k=3), A018853 (k=4), A018872 (k=5), this sequence (k=6), A018876 (k=7), A018878 (k=8), A018880 (k=9), A018882 (k=10).

Formula

a(n^6) = n for n >= 0. - Seiichi Manyama, Jan 30 2017

Extensions

Added initial 0. - Seiichi Manyama, Jan 30 2017

A018876 a(n)^7 is smallest seventh power beginning with n.

Original entry on oeis.org

0, 1, 3, 12, 9, 34, 13, 5, 7, 37, 10, 38, 2, 28, 76, 55, 4, 15, 21, 11, 8, 3, 58, 42, 22, 114, 16, 6, 116, 84, 117, 44, 85, 119, 23, 12, 167, 45, 234, 63, 88, 17, 33, 46, 89, 24, 173, 9, 174, 65, 47, 91, 34, 127, 66, 92, 128, 248, 48, 129, 67, 18, 13, 181, 35, 351, 131, 49, 183, 95, 255
Offset: 0

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Examples

			a(2)=3, because 3^7=2187 is the first 7th power with the most significant digit 2;
a(16)=4, because 4^7=16384 is the first 7th power whose two most significant digits are 16.
		

Crossrefs

Cf. A018851 (k=2), A018852 (k=3), A018853 (k=4), A018872 (k=5), A018874 (k=6), this sequence (k=7), A018878 (k=8), A018880 (k=9), A018882 (k=10).

Formula

a(n^7) = n for n >= 0. - Seiichi Manyama, Jan 30 2017

Extensions

Added initial 0. - Seiichi Manyama, Jan 30 2017

A018878 a(n)^8 is smallest eighth power beginning with n.

Original entry on oeis.org

0, 1, 2, 5, 9, 7, 3, 23, 13, 42, 10, 18, 58, 78, 14, 25, 6, 34, 81, 61, 26, 11, 35, 47, 63, 2, 113, 85, 27, 86, 115, 65, 87, 49, 277, 37, 66, 21, 158, 5, 67, 283, 12, 9, 286, 51, 287, 91, 289, 122, 29, 69, 123, 39, 22, 93, 221, 7, 222, 125, 94, 223, 53, 126, 71, 3, 95, 127, 226, 17
Offset: 0

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Author

Keywords

Comments

a(2)=2, because 2^8=256 is the first 8th power with the most significant decimal digit equal to 2;
a(16)=6, because 6^8=1679616 is the first 8th power with two most significant decimal digits equal to 16.

Crossrefs

Cf. A018851 (k=2), A018852 (k=3), A018853 (k=4), A018872 (k=5), A018874 (k=6), A018876 (k=7), this sequence (k=8), A018880 (k=9), A018882 (k=10).

Formula

a(n^8) = n for n >= 0. - Seiichi Manyama, Jan 30 2017

Extensions

Added initial 0. - Seiichi Manyama, Jan 30 2017

A018880 a(n)^9 is smallest ninth power beginning with n.

Original entry on oeis.org

0, 1, 4, 9, 7, 2, 16, 21, 59, 46, 6, 17, 22, 8, 29, 63, 38, 137, 23, 3, 14, 109, 141, 11, 184, 86, 4, 52, 87, 188, 113, 68, 19, 191, 148, 32, 149, 193, 9, 54, 7, 117, 91, 152, 118, 71, 33, 92, 154, 332, 43, 2, 93, 201, 26, 121, 261, 94, 73, 122, 34, 44, 264, 57, 123, 343, 74, 344, 16
Offset: 0

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Author

Keywords

Crossrefs

Cf. A018851 (k=2), A018852 (k=3), A018853 (k=4), A018872 (k=5), A018874 (k=6), A018876 (k=7), A018878 (k=8), this sequence (k=9), A018882 (k=10).

Formula

a(n^9) = n for n >= 0. - Seiichi Manyama, Jan 30 2017

Extensions

Added initial 0. - Seiichi Manyama, Jan 30 2017

A018882 a(n)^10 is smallest tenth power beginning with n.

Original entry on oeis.org

0, 1, 7, 9, 23, 3, 6, 49, 31, 5, 2, 32, 81, 13, 26, 33, 21, 42, 67, 85, 17, 43, 86, 109, 69, 11, 22, 35, 7, 28, 56, 89, 71, 113, 9, 18, 36, 72, 91, 182, 115, 23, 29, 58, 116, 232, 185, 147, 37, 74, 148, 59, 47, 94, 375, 188, 75, 15, 189, 3, 6, 12, 38, 24, 48, 152, 96, 121, 192, 305
Offset: 0

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Author

Keywords

Crossrefs

Cf. A018851 (k=2), A018852 (k=3), A018853 (k=4), A018872 (k=5), A018874 (k=6), A018876 (k=7), A018878 (k=8), A018880 (k=9), this sequence (k=10).

Formula

a(n^10) = n for n >= 0. - Seiichi Manyama, Jan 30 2017

Extensions

Added initial 0. - Seiichi Manyama, Jan 30 2017

A018797 Smallest cube that begins with n.

Original entry on oeis.org

0, 1, 27, 343, 4096, 512, 64, 729, 8, 9261, 1000, 110592, 125, 1331, 140608, 15625, 166375, 1728, 185193, 19683, 205379, 216, 226981, 238328, 24389, 250047, 262144, 27, 287496, 29791, 300763, 314432, 32768, 3375, 343, 35937, 3652264, 373248
Offset: 0

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Author

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Crossrefs

Programs

  • Mathematica
    a[n_] := For[idn = IntegerDigits[n]; k = 1, True, k++, idk = IntegerDigits[k^3]; If[Length[idn] <= Length[idk], If[idk[[1 ;; Length[idn]]] == idn, Return[k^3]]]]; Table[an = a[n]; Print["a(", n, ") = ", an]; an, {n, 1, 1000}] (* Jean-François Alcover, Mar 13 2016 *)
    id[n_]:=With[{idn=IntegerDigits[n]},idn==Take[IntegerDigits[#], Length[ idn]]&]; With[{c=Range[0,250]^3},Table[SelectFirst[c,id[k]],{k,0,40}]]//Quiet (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Dec 08 2018 *)
  • Python
    for n in range(1, 10**3):
      for k in range(10**3):
        if str(k**3).startswith(str(n)):
          print(k**3, end=', ')
          break
      n += 1 # Derek Orr, Aug 03 2014

Formula

a(n) = A018852(n)^3. - Seiichi Manyama, Jan 30 2017

Extensions

Added initial 0. - Seiichi Manyama, Jan 30 2017

A030669 Cube root of A030668.

Original entry on oeis.org

5, 3, 7, 16, 8, 4, 9, 20, 21, 10, 48, 5, 11, 52, 25, 55, 12, 57, 27, 59, 6, 61, 62, 29, 63, 64, 14, 66, 31, 67, 68, 32, 15, 7, 33, 154, 72, 73, 34, 16, 161, 35, 76, 164, 77, 36, 78, 169, 17, 37, 8, 174, 81, 38, 82, 178, 83, 18, 39, 182, 85, 184, 86, 40, 87, 188
Offset: 1

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Author

Keywords

Comments

a(n) = A018852(n) if n is not a cube. - Robert Israel, Dec 25 2018

Crossrefs

Programs

  • Maple
    f:= proc(n) local d,x;
      for d from 1 do
        x:= ceil((n*10^d)^(1/3));
        if x^3 < (n+1)*10^d then return x fi
      od
    end proc:
    map(f, [$1..100]); # Robert Israel, Dec 25 2018

A138173 a(n) is the smallest m such that m^3 begins with n^2.

Original entry on oeis.org

1, 16, 21, 55, 63, 154, 17, 4, 201, 10, 23, 113, 257, 27, 609, 295, 307, 148, 1535, 342, 164, 1692, 809, 1793, 397, 878, 9, 428, 944, 4482, 987, 1008, 1029, 4872, 107, 2349, 5154, 5247, 2478, 252, 552, 5609, 5697, 5785, 2726, 1284, 2806, 6131, 2885
Offset: 1

Views

Author

Zak Seidov, Mar 05 2008

Keywords

Comments

Differs from A030691.

Crossrefs

Programs

  • Python
    from gmpy2 import iroot
    def A138173(n):
        d, nd = 1, n**2
        while True:
            x = iroot(nd-1,3)[0]+1
            if x**3 < nd+d:
                return int(x)
            d *= 10
            nd *= 10 # Chai Wah Wu, May 24 2016
  • Sage
    A138173 = lambda n: next(m for m in IntegerRange(1, infinity) if str(m**3).startswith(str(n**2)))
    # D. S. McNeil, Dec 12 2010
    

Formula

a(n) = (A138174(n))^(1/3).
Showing 1-10 of 12 results. Next