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.

A169799 First differences of A167209.

Original entry on oeis.org

1, 3, 6, 7, 12, 15, 23, 24, 26, 31, 32, 35, 36, 37, 41, 42, 49, 51, 52, 53, 55, 56, 59, 60, 64, 65, 69, 70, 72, 75, 76, 79, 80, 82, 85, 86, 93, 94, 97, 99, 102, 106, 109, 110, 112, 122, 123, 125, 126, 128, 130, 133, 137, 141, 143, 145, 150, 153, 154, 157, 166, 168, 172, 173, 174, 178, 185, 188, 193, 195, 199, 200
Offset: 1

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Author

N. J. A. Sloane, Sep 03 2014

Keywords

Crossrefs

Extensions

Definition changed because of new offset in A167209. - N. J. A. Sloane, Feb 18 2019

A047699 a(0) = 0; for n >= 0, a(n+1) = a(n) + x where x is the smallest nonnegative number that is not equal to a(i) +- a(k) for any 0 <= i <= n, 0 <= k <= n.

Original entry on oeis.org

0, 1, 4, 10, 17, 29, 44, 66, 89, 113, 139, 170, 202, 237, 273, 311, 352, 394, 445, 497, 550, 605, 664, 728, 796, 871, 948, 1026, 1106, 1188, 1274, 1361, 1452, 1544, 1638, 1735, 1835, 1936, 2038, 2145, 2256, 2372, 2491, 2611, 2736, 2863, 2991
Offset: 0

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Author

K. S. Brown (ksbrown(AT)seanet.com)

Keywords

Comments

A sparse maximal expulsion set under addition.
Note that this is not the sparse expulsion set constructed in Kevin Brown's article, which is A167209. That sequence has 67 where this one has 66.

Examples

			After {0,1,4,10}, 0, 1, 1 + 1, 4, 4 - 1, 1 + 4, 10 - 4, etc. are excluded, but 7 is not, so next term is 10 + 7 = 17.
		

Crossrefs

Programs

  • Mathematica
    a=0;s={a};X=Complement[Range[10^4],{0,a,2a}]; Do[b=a+X[[1]];X=Complement[X,s+b,b-s,{b,2b}];AppendTo[s,b];a=b,{100}];s (* Zak Seidov, Jul 14 2010 *)

Extensions

Corrected by Andrew Weimholt, Jul 13 2010

A169820 1 followed by first differences of A169799.

Original entry on oeis.org

1, 2, 3, 1, 5, 3, 8, 1, 2, 5, 1, 3, 1, 1, 4, 1, 7, 2, 1, 1, 2, 1, 3, 1, 4, 1, 4, 1, 2, 3, 1, 3, 1, 2, 3, 1, 7, 1, 3, 2, 3, 4, 3, 1, 2, 10, 1, 2, 1, 2, 2, 3, 4, 4, 2, 2, 5, 3, 1, 3, 9, 2, 4, 1, 1, 4, 7, 3, 5, 2, 4, 1, 2, 1, 3, 7, 5, 8, 1, 1, 1, 2, 2, 3, 1, 5, 1, 3, 3, 8, 9, 3, 5, 3, 2, 2, 18, 2, 8, 4
Offset: 1

Views

Author

Entry revised by N. J. A. Sloane, Sep 03 2014

Keywords

Comments

Essentially the second differences of A167209.

Crossrefs

Showing 1-3 of 3 results.