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.

A018862 5^a(n) is smallest power of 5 beginning with n.

Original entry on oeis.org

0, 2, 5, 11, 1, 4, 7, 50, 10, 63, 23, 3, 56, 26, 6, 69, 49, 29, 9, 82, 62, 42, 22, 12, 2, 75, 55, 45, 25, 15, 5, 88, 68, 58, 48, 38, 28, 18, 8, 91, 81, 71, 61, 51, 41, 31, 21, 11, 104, 94, 84, 74, 167, 64, 54, 44, 137, 34, 24, 117, 14, 4, 97, 87, 180, 77, 67, 160, 57, 150, 47, 37, 130
Offset: 1

Views

Author

David W. Wilson

Keywords

Links

Crossrefs

Cf. A018861.
Cf. A018858, A018860, A018864, A018866, A018868, A062525, A062526.

Programs

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

A063572 Smallest power of 9 having n in its decimal representation.

Original entry on oeis.org

5, 2, 3, 6, 5, 4, 4, 3, 2, 1, 11, 15, 18, 11, 6, 18, 17, 19, 13, 23, 9, 8, 14, 21, 12, 13, 26, 28, 12, 3, 8, 6, 13, 24, 10, 18, 12, 27, 9, 27, 10, 6, 9, 8, 6, 14, 8, 7, 9, 5, 18, 16, 18, 6, 13, 35, 4, 20, 13, 5, 11, 4, 23, 18, 12, 4, 17, 8, 24, 7, 22, 17, 3
Offset: 0

Views

Author

Robert G. Wilson v, Aug 10 2001

Keywords

Comments

Variant of A062526. - R. J. Mathar, Dec 15 2008

Programs

  • Mathematica
    a = {}; Do[k = 1; While[ StringPosition[ ToString[9^k], ToString[n] ] == {}, k++ ]; a = Append[a, k], {n, 0, 60} ]; a
  • Python
    def a(n):
  target, k, pow9 = str(n), 1, 9
  while not target in str(pow9): k, pow9 = k+1, pow9*9
  return k
print([a(n) for n in range(73)]) # Michael S. Branicky, May 02 2021

Extensions

More terms from Michael S. Branicky, May 02 2021

A176769 Smallest power of 9 whose decimal expansion contains n.

Original entry on oeis.org

59049, 1, 729, 531441, 59049, 6561, 6561, 729, 81, 9, 31381059609, 205891132094649, 150094635296999121, 31381059609, 531441, 150094635296999121, 16677181699666569, 1350851717672992089, 2541865828329, 8862938119652501095929
Offset: 0

Views

Author

Jonathan Vos Post, Apr 25 2010

Keywords

Comments

This is to 9 as A176763 is to 3 and as A030001 is to 2.

Examples

			a(1) = 1 because 9^0 = 1 has "1" as a substring (not a proper substring, though).
a(2) = 729 because 9^3 = 729 has "2" as a substring.
a(3) = 531441 because 9^6 = 531441 has "3" as a substring.

Links

Crossrefs

Cf. A001018, A030001, A176763, A176764-A176773.

Programs

  • Mathematica
    A176769[n_] := Block[{k = -1}, While[StringFreeQ[IntegerString[9^++k], IntegerString[n]]]; 9^k]; Array[A176769, 50, 0] (* Paolo Xausa, Apr 04 2024 *)

Formula

a(n) = MIN{A001019(i) such that n in decimal representation is a substring of A001019(i)}.
a(n) = 9^A062526(n). - Michel Marcus, Sep 30 2014

Extensions

More terms from Sean A. Irvine and Jon E. Schoenfield, May 05 2010
a(0) prepended by Paolo Xausa, Apr 04 2024
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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