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.

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A135454 Number of sums payable using exactly n banknotes of denominations 1, 5, 10, 20, 50, 100.

Original entry on oeis.org

1, 6, 21, 52, 103, 174, 262, 360, 461, 561, 660, 759, 858, 957, 1056, 1155, 1254, 1353, 1452, 1551, 1650, 1749, 1848, 1947, 2046, 2145, 2244, 2343, 2442, 2541, 2640, 2739, 2838, 2937, 3036, 3135, 3234, 3333, 3432, 3531, 3630, 3729, 3828
Offset: 0

Views

Author

Zak Seidov, Feb 16 2008

Keywords

Examples

			n=1: 6 payable sums are 1,5,10,20,50,100;
n=3: the 52 sums are in A135137.
		

Extensions

Corrected and extended by Joshua Zucker, Feb 16 2008

A135526 Number of sums payable using exactly n banknotes of denominations 1, 5, 10, 20, 50, 100 (change allowable).

Original entry on oeis.org

1, 6, 33, 95, 188, 288, 388, 488, 588, 688, 788, 888, 988, 1088, 1188, 1288, 1388, 1488, 1588, 1688, 1788, 1888, 1988, 2088, 2188, 2288, 2388, 2488, 2588, 2688, 2788, 2888, 2988, 3088, 3188, 3288, 3388, 3488, 3588, 3688, 3788, 3888, 3988, 4088, 4188, 4288
Offset: 0

Views

Author

Zak Seidov, Feb 20 2008

Keywords

Comments

Terms and formula from Max Alekseyev and Robert Israel.

Crossrefs

Programs

  • Mathematica
    Join[{1,6,33,95}, LinearRecurrence[{2,-1},{188,288},25]] (* or *) Join[{1,6,33,95}, Table[100*n -212, {n,4,25}]] (* G. C. Greubel, Oct 17 2016 *)
  • PARI
    a(n)=if(n>3,100*n-212,[1,6,33,95][n+1]) \\ Charles R Greathouse IV, Jun 23 2024

Formula

a(n) = 100*n - 212 for n>=4.
From G. C. Greubel, Oct 17 2016: (Start)
a(n) = 2*a(n-1) - a(n-2), for n >= 4.
G.f.: (1 + 4*x + 22*x^2 + 35*x^3 + 31*x^4 + 7*x^5)/(1-x)^2.
E.g.f.: (1/6)*( 1278 + 708*x + 135*x^2 + 7*x^3 - 24*(53 - 25*x)*exp(x) ). (End)

Extensions

Extended by Max Alekseyev, Mar 04 2009
Showing 1-2 of 2 results.