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

Author

Omar E. Pol, Apr 02 2008

Keywords

• base
• easy
• nonn

Comments

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

Examples

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

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..10000
• Index entries for sequences related to Benford's law

Crossrefs

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

Programs

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 *)