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 1-4 of 4 results.

A240813 Triangle read by rows: T(n,k) (n >= 1, 1 <= k <= n) = length (or lifetime) of the meta-Fibonacci sequence f(1) = ... = f(n) = 1; f(i)=f(i-f(i-k))+f(i-f(i-n)) if that sequence is only defined for finitely many terms, or 0 if that sequence is infinite.

Original entry on oeis.org

6, 0, 14, 164, 54, 13, 0, 0, 10, 11, 60, 37, 11, 12, 13, 2354, 30, 13, 13, 14, 15, 282, 63, 44, 14, 15, 17, 18, 1336, 368, 31, 15, 17, 18, 19, 20, 100, 47, 49, 17, 18, 19, 20, 21, 22, 1254, 46, 38, 18, 19, 20, 21, 22, 23, 24, 366, 108, 80, 19, 20, 21, 22, 23
Offset: 1

Views

Author

N. J. A. Sloane, Apr 15 2014

Keywords

Comments

The zero entries (except T(4,1)) are only conjectural.

Examples

			Triangle begins:
6,
0, 14,
164, 54, 13,
0, 0, 10, 11,
60, 37, 11, 12, 13,
2354, 30, 13, 13, 14, 15,
282, 63, 44, 14, 15, 17, 18,
1336, 368, 31, 15, 17, 18, 19
...
		

References

  • D. R. Hofstadter, Curious patterns and non-patterns in a family of meta-Fibonacci recursions, Lecture in Doron Zeilberger's Experimental Mathematics Seminar, Rutgers University, April 10 2014.

Crossrefs

Diagonals give A134680, A240811, A240812.
See A240816 for another version.

Extensions

More terms from Lars Blomberg, Oct 24 2014

A240810 a(n) = index of first nonexisting term of the meta-Fibonacci sequence {f(1) = ... = f(n) = 1; f(k)=f(k-f(k-1))+f(k-f(k-n))} if that sequence is only defined for finitely many terms, or 0 if that sequence is infinite.

Original entry on oeis.org

7, 0, 165, 0, 61, 2355, 283, 1337, 101, 1255, 367, 420, 499, 484, 779, 1205, 293, 374, 846, 839, 1119, 2121, 816, 2617, 687, 1196, 746, 1113, 2133, 1589, 755, 1228, 1280, 1662, 717, 2276, 785, 2342, 1875, 1464, 1123, 2801, 1351, 1614, 2280, 1558, 1533
Offset: 1

Views

Author

N. J. A. Sloane, Apr 15 2014

Keywords

Comments

a(2)=0 is only a conjecture (see A005185), whereas a(4)=0 is a theorem of Balamohan et al. (2007).
Except for the two zero entries, this is equal to A134680(n)+1. See that entry for further information.

Crossrefs

See A134680 for another version.
A diagonal of the triangle in A240816.

A240818 a(n) = length (or lifetime) of the meta-Fibonacci sequence f(k) = k for k <= n; f(k)=f(k-f(k-1))+f(k-f(k-n)) if that sequence is only defined for finitely many terms, or 0 if that sequence is infinite.

Original entry on oeis.org

6, 0, 162, 0, 56, 2349, 276, 1300, 84, 1245, 356, 408, 486, 470, 764, 1172, 258, 356, 805, 819, 1078, 2099, 470, 2593, 662, 1170, 665, 1085, 2104, 1417, 724, 1196, 1247, 1628, 648, 2240, 712, 2304, 1836, 1424, 1082, 2759, 1264, 1570, 2235, 1512, 1442, 2447
Offset: 1

Views

Author

N. J. A. Sloane, Apr 15 2014

Keywords

Comments

The terms a(2) = 0 and a(4) = 0 are only conjectural.
This sequence is very similar to A134680.

References

  • D. R. Hofstadter, Curious patterns and non-patterns in a family of meta-Fibonacci recursions, Lecture in Doron Zeilberger's Experimental Mathematics Seminar, Rutgers University, April 10 2014.

Crossrefs

The sequences for n=2,3,4 are A005185 and (essentially) A046700, A063882.
See A240822 for another version.
A diagonal of the triangle in A240821.
Cf. A134680.

Extensions

More terms from Lars Blomberg, Oct 24 2014

A240822 a(n) = index of first nonexisting term of the meta-Fibonacci sequence {f(k) = k for k <= n; f(k)=f(k-f(k-1))+f(k-f(k-n))} if that sequence is only defined for finitely many terms, or 0 if that sequence is infinite.

Original entry on oeis.org

7, 0, 163, 0, 57, 2350, 277, 1301, 85, 1246, 357, 409, 487, 471, 765, 1173, 259, 357, 806, 820, 1079, 2100, 471, 2594, 663, 1171, 666, 1086, 2105, 1418, 725, 1197, 1248, 1629, 649, 2241, 713, 2305, 1837, 1425, 1083, 2760, 1265, 1571, 2236, 1513, 1443, 2448
Offset: 1

Views

Author

N. J. A. Sloane, Apr 15 2014

Keywords

Comments

a(2)=0 and a(4)=0 are conjectural.
Except for the two zero entries, this is equal to A240818(n)+1. See that entry for further information.
Similar to A134680 and A240810.

Crossrefs

See A240818 for another version.
A diagonal of the triangle in A240825.

Extensions

More terms from Max Alekseyev, Sep 19 2023
Showing 1-4 of 4 results.