A061489 Numbers that are Fibonacci numbers plus or minus 1.

0, 1, 2, 3, 4, 6, 7, 9, 12, 14, 20, 22, 33, 35, 54, 56, 88, 90, 143, 145, 232, 234, 376, 378, 609, 611, 986, 988, 1596, 1598, 2583, 2585, 4180, 4182, 6764, 6766, 10945, 10947, 17710, 17712, 28656, 28658, 46367, 46369, 75024, 75026, 121392, 121394, 196417

Offset

1,3

Comments

Only the first four terms are Fibonacci numbers per se. - Alonso del Arte, Oct 05 2017

Links

Harry J. Smith, Table of n, a(n) for n=1..500

Ron Knott, The Mathematical Magic of the Fibonacci Numbers.

Index entries for linear recurrences with constant coefficients, signature (-1,1,1,1,1).

Formula

a(n) = -a(n-1) + a(n-2) + a(n-3) + a(n-4) + a(n+5), for n >= 10. - Amiram Eldar, Jun 24 2023

Mathematica

Union[Table[Fibonacci[i] - 1, {i, 30}], Table[Fibonacci[j] + 1, {j, 0, 30}]]
Union[Flatten[# + {1, -1} &/@ Fibonacci[Range[30]]]] (* Harvey P. Dale, Dec 26 2015 *)

Prog

(PARI) { t="b061489.txt"; for (n=1, 4, write(t, n, " ", n - 1) ); g=3; h=2; for (n=3, 250, f=g + h; h=g; g=f; write(t, 2*n - 1, " ", f - 1); write(t, 2*n, " ", f + 1) ) } \\ Harry J. Smith, Jul 23 2009

Crossrefs

Cf. A000071, A001611 (the union of those two sequences forms this sequence).

Sequence in context: A145803 A018629 A018357 * A117595 A050050 A222801

Adjacent sequences: A061486 A061487 A061488 * A061490 A061491 A061492

Keyword

nonn,easy

Author

N. J. A. Sloane, Nov 08 2001

Extensions

More terms from Robert G. Wilson v, Nov 12 2001

Status

approved