A088133 Sum of first and last digits of n. Different from A115299.

0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 8, 9, 10, 11, 12, 13, 14

Offset

0,2

Links

Table of n, a(n) for n=0..86.

Formula

a(n) = A000030(n) + A010879(n). - M. F. Hasler, Apr 22 2024

Mathematica

Total[{First[IntegerDigits[#]], Last[IntegerDigits[#]]}]&/@Range[90] (* Harvey P. Dale, Aug 21 2018 *)

Prog

(PARI) apply( {A088133(n)=n\10^logint(n+!n, 10)+n%10}, [0..99]) \\ M. F. Hasler, Apr 22 2024
(Python) list(map(A088133 := lambda n: int(str(n)[0])+n%10, range(99))) # M. F. Hasler, Apr 22 2024

Crossrefs

Cf. A000030 (first digit of n), A010879 (last digit of n).

Cf. A046704, A007953, A088134, A088135, A088136.

Sequence in context: A100817 A074157 A076309 * A115299 A076312 A061762

Adjacent sequences: A088130 A088131 A088132 * A088134 A088135 A088136

Keyword

easy,nonn,base

Author

Zak Seidov, Sep 20 2003

Extensions

Extended to a(0) = 0 by M. F. Hasler, Apr 22 2024

Status

approved