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A088133
Sum of first and last digits of n. Different from A115299.
9
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
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).
Sequence in context: A100817 A074157 A076309 * A115299 A076312 A061762
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