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.

Previous Showing 11-18 of 18 results.

A005343 a(n) = solution to the postage stamp problem with n denominations and 8 stamps.

Original entry on oeis.org

8, 28, 89, 234, 512, 1045, 2001, 3485
Offset: 1

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Author

Keywords

Comments

Fred Lunnon [W. F. Lunnon] defines "solution" to be the smallest value not obtainable by the best set of stamps. The solutions given are one lower than this, that is, the sequence gives the largest number obtainable without a break using the best set of stamps.

References

  • R. K. Guy, Unsolved Problems in Number Theory, C12.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Extensions

Entry improved by comments from John Seldon (johnseldon(AT)onetel.com), Sep 15 2004
a(8) from Challis and Robinson. John P Robinson (john-robinson(AT)uiowa.edu), Feb 18 2010

A005344 a(n) = solution to the postage stamp problem with n denominations and 9 stamps.

Original entry on oeis.org

9, 34, 112, 326, 797, 1617, 3191
Offset: 1

Views

Author

Keywords

Comments

Fred Lunnon [W. F. Lunnon] defines "solution" to be the smallest value not obtainable by the best set of stamps. The solutions given are one lower than this, that is, the sequence gives the largest number obtainable without a break using the best set of stamps.

References

  • R. K. Guy, Unsolved Problems in Number Theory, C12.
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Extensions

Entry improved by comments from John Seldon (johnseldon(AT)onetel.com), Sep 15 2004
a(7) from Challis and Robinson by Robert Price, Jul 19 2013

A053346 a(n) = solution to the postage stamp problem with 7 denominations and n stamps.

Original entry on oeis.org

7, 26, 70, 162, 336, 638, 1137, 2001, 3191, 5047, 7820, 11568, 17178
Offset: 1

Views

Author

N. J. A. Sloane, Jun 20 2003

Keywords

Comments

Fred Lunnon [W. F. Lunnon] defines "solution" to be the smallest value not obtainable by the best set of stamps. The solutions given are one lower than this, that is, the sequence gives the largest number obtainable without a break using the best set of stamps.

References

  • R. K. Guy, Unsolved Problems in Number Theory, C12.

Crossrefs

Extensions

a(9) from Challis by R. J. Mathar, Apr 01 2006
Entry improved by comments from John Seldon (johnseldon(AT)onetel.com), Sep 15 2004
a(10)-a(13) from Challis and Robinson by Robert Price, Jul 19 2013

A075060 a(n) = solution to the postage stamp problem with n denominations and 10 stamps.

Original entry on oeis.org

10, 40, 146, 427, 1055, 2510, 5047
Offset: 1

Views

Author

N. J. A. Sloane, Jun 20 2003

Keywords

Comments

Fred Lunnon [W. F. Lunnon] defines "solution" to be the smallest value not obtainable by the best set of stamps. The solutions given are one lower than this, that is, the sequence gives the largest number obtainable without a break using the best set of stamps.

References

  • R. K. Guy, Unsolved Problems in Number Theory, C12.

Crossrefs

Extensions

Entry improved by comments from John Seldon (johnseldon(AT)onetel.com), Sep 15 2004
a(7) from Challis and Robinson by John P Robinson (john-robinson(AT)uiowa.edu), Feb 18 2010

A084192 Array read by antidiagonals: T(n,k) = solution to postage stamp problem with n stamps and k denominations (n >= 1, k >= 1).

Original entry on oeis.org

1, 2, 2, 3, 4, 3, 4, 8, 7, 4, 5, 12, 15, 10, 5, 6, 16, 24, 26, 14, 6, 7, 20, 36, 44, 35, 18, 7, 8, 26, 52, 70, 71, 52, 23, 8, 9, 32, 70, 108, 126, 114, 69, 28, 9, 10, 40, 93, 162, 211, 216, 165, 89, 34, 10, 11, 46, 121, 228, 336, 388, 345, 234, 112, 40, 11, 12, 54, 154, 310, 524
Offset: 0

Views

Author

N. J. A. Sloane, Jun 20 2003

Keywords

Comments

Fred Lunnon [W. F. Lunnon] defines "solution" to be the smallest value not obtainable by the best set of stamps. The solutions given in this sequence and in A001208, A001209, A001210, A001211, A001212, ... are one lower than this, that is, the sequence gives the largest number obtainable without a break using the best set of stamps.

Examples

			Array begins:
   1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11, ...
   2,   4,   7,  10,  14,  18,  23,  28,  34,  40, ...
   3,   8,  15,  26,  35,  52,  69,  89, 112, ...
   4,  12,  24,  44,  71, 114, 165, 234, ...
   5,  16,  36,  70, 126, 216, 345, ...
   6,  20,  52, 108, 211, 388, ...
   7,  26,  70, 162, 336, ...
   8,  32,  93, 228, ...
   9,  40, 121, ...
  10,  46, ...
  11, ...
  ...
		

Crossrefs

Extensions

Entry improved by comments from John Seldon (johnseldon(AT)onetel.com), Sep 15 2004
More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Jun 26 2003
Comments corrected by Shawn Pedersen, Apr 17 2012

A084193 Array read by antidiagonals: T(k,n) = solution to postage stamp problem with n stamps and k denominations (n >= 1, k >= 1).

Original entry on oeis.org

1, 2, 2, 3, 4, 3, 4, 7, 8, 4, 5, 10, 15, 12, 5, 6, 14, 26, 24, 16, 6, 7, 18, 35, 44, 36, 20, 7, 8, 23, 52, 71, 70, 52, 26, 8, 9, 28, 69, 114, 126, 108, 70, 32, 9, 10, 34, 89, 165, 216, 211, 162, 93, 40, 10, 11, 40, 112, 234, 345, 388, 336, 228, 121, 46, 11, 12, 47, 146, 326, 512
Offset: 0

Views

Author

N. J. A. Sloane, Jun 20 2003

Keywords

Comments

Fred Lunnon [W. F. Lunnon] defines "solution" to be the smallest value not obtainable by the best set of stamps. The solutions given in this sequence and in A001208, A001209, A001210, A001211, A001212, ... are one lower than this, that is, the sequence gives the largest number obtainable without a break using the best set of stamps.

Examples

			Array begins:
   1,   2,   3,   4,   5,   6,   7,   8,   9,  10,  11, ...
   2,   4,   8,  12,  16,  20,  26,  32,  40,  46, ...
   3,   7,  15,  24,  36,  52,  70,  93, 121, ...
   4,  10,  26,  44,  70, 108, 162, 228, ...
   5,  14,  35,  71, 126, 211, 336, ...
   6,  18,  52, 114, 216, 388, ...
   7,  23,  69, 165, 345, ...
   8,  28,  89, 234, ...
   9,  34, 112, ...
  10,  40, ...
  11, ...
  ...
		

Crossrefs

A084192 gives transposed array. Rows and columns give rise to A014616, A001208, A001209, A001210, A001211, A053346, A053348, A001212, A001213, A001214, A001215, A001216, A005342, A005343, A005344, A075060.

Extensions

Entry improved by comments from John Seldon (johnseldon(AT)onetel.com), Sep 15 2004
More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Jun 26 2003
Comments corrected by Shawn Pedersen, Apr 17 2012

A114139 Changes in United States postal rates per ounce since 1863.

Original entry on oeis.org

-2, -2, 1, -1, 1, 1, 1, 1, 2, 2, 0, 3, 2, 3, 2, 2, 3, 4, 3, 3, 1, 1, 3, 2
Offset: 1

Views

Author

Jonathan Vos Post, Feb 03 2006

Keywords

Comments

Benjamin Franklin, first Postmaster General of the United States, applied computational complexity theory to Economics by changing the business plan for American mail by changing from payment by distance to payment by weight. "Before stamps were used a person had to collect his mail at the post office and pay for it. Franklin stopped the money loss on unclaimed mail in Philadelphia by printing in his paper the names of persons who had mail awaiting them. He also developed a simple, accurate way of keeping post-office accounts. In 1753 Franklin was made deputy postmaster general for all the colonies." [Encyclopedia Britannica]

Examples

			a(1) = -2 because the rate per half ounce was lowered effective 3 March 1863 from 3 cents to 2 cents; thereafter rates were per ounce.
		

References

  • R. K. Guy, Unsolved Problems in Number Theory, C12.

Crossrefs

A140571 Decimal expansion of the universal constant in E(h), the maximum number of essential elements of order h.

Original entry on oeis.org

2, 0, 5, 7, 2, 8, 4, 1, 2, 8, 4, 7, 8, 7, 9, 3, 4, 1, 2, 8, 5, 8, 2, 2, 3, 9, 6, 4, 4, 8, 3, 7, 6, 9, 0, 9, 1, 0, 0, 4, 3, 4, 7, 8, 2, 7, 4, 9, 4, 2, 1, 2, 6, 8, 0, 7, 4, 1, 5, 3, 8, 1, 9, 6, 6, 2, 4, 2, 3, 6, 9, 2, 9, 5, 4, 2, 7, 6, 3, 5, 1, 3, 3, 4, 9, 8, 5, 1, 9, 0, 8, 0, 7, 8, 9, 0, 1, 6, 5, 3, 6, 5, 5, 9, 7, 7
Offset: 1

Views

Author

Jonathan Vos Post, Jul 05 2008

Keywords

Comments

A fundamental result of Erdos and Graham is that every integer basis possesses only finitely many essential elements. Grekos refined this, showing that the number of essential elements in a basis or order h is bounded by a function of h only. Deschamps and Farhi (2007) proved a best possible upper bound on this function, which contains a constant whose digits are this sequence.
Abstract: Plagne recently determined the asymptotic behavior of the function E(h), which counts the maximum possible number of essential elements in an additive basis for N of order h. Here we extend his investigations by studying asymptotic behavior of the function E(h,k), which counts the maximum possible number of essential subsets of size k, in a basis of order h. For a fixed k and with h going to infinity, we show that
E(h,k) = Theta_{k} ([h^{k}/log h]^{1/(k+1)}). The determination of a more precise asymptotic formula is shown to depend on the solution of the well-known "postage stamp problem" in finite cyclic groups. On the other hand, with h fixed and k going to infinity, we show that E(h,k) ~ (h-1) (log k)/(log log k).

Examples

			2.0572841284787934...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[(30*Sqrt[Log[1564]/1564]),10,120][[1]] (* Harvey P. Dale, Sep 27 2023 *)
  • PARI
    30*sqrt(log(1564)/1564) \\ Michel Marcus, Oct 18 2018

Formula

Equals 30*sqrt(log(1564)/1564).

Extensions

a(100) corrected by Georg Fischer, Jul 12 2021
Previous Showing 11-18 of 18 results.