|
Search: id:A014616
|
|
|
| A014616 |
|
a(n) = solution to the postage stamp problem with 2 denominations and n stamps. |
|
+0
21
|
|
| 2, 4, 7, 10, 14, 18, 23, 28, 34, 40, 47, 54, 62, 70, 79, 88, 98, 108, 119, 130, 142, 154, 167, 180, 194, 208, 223, 238, 254, 270, 287, 304, 322, 340, 359, 378, 398, 418, 439, 460, 482, 504, 527, 550, 574, 598, 623, 648, 674, 700, 727, 754, 782, 810, 839, 868
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
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.
a(n) = A002620(n+2)-2.
|
|
REFERENCES
|
R. K. Guy, Unsolved Problems in Number Theory, C12.
Amitabha Tripathi, A Note on the Postage Stamp Problem, Journal of Integer Sequences, Vol. 9 (2006), Article 06.1.3.
|
|
LINKS
|
Erich Friedman, Postage stamp problem
Eric Weisstein's World of Mathematics, Postage stamp problem
Hugh Thomas and Stephanie van Willigenburg, Compact symmetric solutions to the postage stamp problem
|
|
FORMULA
|
a(n) = floor((n^2 + 6*n + 1)/4).
|
|
CROSSREFS
|
Postage stamp sequences: A001208 A001209 A001210 A001211 A001212 A001213 A001214 A001215 A001216 A005342 A005343 A005344 A014616 A053346 A053348 A075060 A084192 A084193
Sequence in context: A130251 A024611 A088236 this_sequence A120679 A127723 A076268
Adjacent sequences: A014613 A014614 A014615 this_sequence A014617 A014618 A014619
|
|
KEYWORD
|
nonn,nice,easy
|
|
AUTHOR
|
Eric Weisstein (eric(AT)weisstein.com)
|
|
EXTENSIONS
|
Entry improved by comments from John Seldon (johnseldon(AT)onetel.com), Sep 15 2004
More terms from John W. Layman (layman(AT)math.vt.edu), Apr 13 1999
|
|
|
Search completed in 0.002 seconds
|
