A138844 Concatenation of initial and final digits of n-th positive Fibonacci number.

11, 11, 22, 33, 55, 88, 13, 21, 34, 55, 89, 14, 23, 37, 60, 97, 17, 24, 41, 65, 16, 11, 27, 48, 75, 13, 18, 31, 59, 80, 19, 29, 38, 57, 95, 12, 27, 39, 66, 15, 11, 26, 47, 73, 10, 13, 23, 46, 79, 15, 24, 39, 53, 82, 15, 27, 32, 59, 91, 10, 21, 41, 62, 13, 15, 28, 43, 71, 14

Offset

1,1

Comments

Also, concatenation of A008963(n) and A003893(n).

Links

Alois P. Heinz, Table of n, a(n) for n = 1..10000

Index entries for sequences related to Benford's law

Example

a(15) = 60 because the 15th positive Fibonacci number is 610 and the concatenation of initial and final digits of 610 is 60.

Maple

a:= n-> (f-> parse(cat(f[1], f[-1])))(""||(combinat[fibonacci](n))):
seq(a(n), n=1..92);  # Alois P. Heinz, Nov 23 2023

Mathematica

FromDigits[Join[{IntegerDigits[#][[1]]}, {IntegerDigits[#][[-1]]}]]&/@ Fibonacci[Range[70]] (* Harvey P. Dale, Jun 15 2018 *)

Crossrefs

Cf. A000045, A003893, A008963, A073729, A138840, A138841, A138842, A138843.

Sequence in context: A110414 A040111 A003887 * A022345 A246554 A218163

Adjacent sequences: A138841 A138842 A138843 * A138845 A138846 A138847

Keyword

base,easy,nonn

Author

Omar E. Pol, Apr 02 2008

Status

approved