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.

A117821 a(0) = a(1) = 1; for n >= 2, a(n) = a(n-1) + a(n-2) - n if that number is positive and not already in the sequence, otherwise a(n) = a(n-1) + a(n-2) + n.

Original entry on oeis.org

1, 1, 4, 2, 10, 7, 11, 25, 28, 44, 62, 95, 145, 227, 358, 570, 912, 1465, 2359, 3805, 6144, 9928, 16050, 25955, 41981, 67911, 109866, 177750, 287588, 465309, 752867, 1218145, 1970980, 3189092, 5160038, 8349095, 13509097, 21858155, 35367214
Offset: 0

Views

Author

N. J. A. Sloane, Apr 30 2006

Keywords

Crossrefs

Cf. A005132, A079053, A117822, A117823, A117824.

Programs

  • Maple
    a[0]:=1: a[1]:=1: A:={1}: for n from 2 to 40 do if a[n-1]+a[n-2]-n>0 and member(a[n-1]+a[n-2]-n,A)=false then a[n]:=a[n-1]+a[n-2]-n: A:=A union {a[n-1]+a[n-2]-n} else a[n]:=a[n-1]+a[n-2]+n: A:=A union {a[n-1]+a[n-2]+n} fi: od: seq(a[n],n=0..40); # Emeric Deutsch, Apr 30 2006

Extensions

More terms from Benoit Cloitre and Emeric Deutsch, Apr 30 2006

A117823 a(0) = 0, a(1) = 1; for n >= 2, a(n) = a(n-1) + a(n-2) - n if that number is positive and not already in the sequence, otherwise a(n) = a(n-1) + a(n-2) + n.

Original entry on oeis.org

0, 1, 3, 7, 6, 8, 20, 21, 33, 45, 68, 102, 158, 247, 391, 623, 998, 1604, 2584, 4169, 6733, 10881, 17592, 28450, 46018, 74443, 120435, 194851, 315258, 510080, 825308, 1335357, 2160633, 3495957, 5656556, 9152478, 14808998, 23961439, 38770399
Offset: 0

Views

Author

N. J. A. Sloane, Apr 30 2006

Keywords

Crossrefs

Cf. A005132, A079053, A117821, A117822, A117824.

Programs

  • Maple
    a[0]:=0: a[1]:=1: A:={0,1}: for n from 2 to 42 do if a[n-1]+a[n-2]-n>0 and member(a[n-1]+a[n-2]-n,A)=false then a[n]:=a[n-1]+a[n-2]-n: A:=A union {a[n-1]+a[n-2]-n} else a[n]:=a[n-1]+a[n-2]+n: A:=A union {a[n-1]+a[n-2]+n} fi: od: seq(a[n],n=0..42); # Emeric Deutsch, Apr 30 2006

Extensions

More terms from Emeric Deutsch, Apr 30 2006

A117824 a(0) = 0, a(1) = 1; for n >= 2, a(n) = a(n-1) + a(n-2) - (n-1) if that number is positive and not already in the sequence, otherwise a(n) = a(n-1) + a(n-2) + (n-1).

Original entry on oeis.org

0, 1, 2, 5, 4, 13, 12, 19, 24, 35, 50, 75, 114, 177, 278, 441, 704, 1129, 1816, 2927, 4724, 7631, 12334, 19943, 32254, 52173, 84402, 136549, 220924, 357445, 578340, 935755, 1514064, 2449787, 3963818, 6413571, 10377354, 16790889, 27168206, 43959057
Offset: 0

Views

Author

N. J. A. Sloane, Apr 30 2006

Keywords

Crossrefs

Cf. A005132, A079053, A117821, A117822, A117823.

Programs

  • Maple
    a[0]:=0: a[1]:=1: A:={0,1}: for n from 2 to 42 do if a[n-1]+a[n-2]-n+1>0 and member(a[n-1]+a[n-2]-n+1,A)=false then a[n]:=a[n-1]+a[n-2]-n+1: A:=A union {a[n-1]+a[n-2]-n+1} else a[n]:=a[n-1]+a[n-2]+n-1: A:=A union {a[n-1]+a[n-2]+n-1} fi: od: seq(a[n],n=0..42); # Emeric Deutsch, Apr 30 2006

Extensions

More terms from Emeric Deutsch, Apr 30 2006
Showing 1-3 of 3 results.

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

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