OFFSET
1,13
LINKS
David F. Marrs, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = abs(floor(n / 10 ^ floor(log_10(n))) - (n - floor(n / 10) * 10)) - David F. Marrs, Oct 14 2018
EXAMPLE
a(371) = abs(3 - 1) = 2.
a(567) = abs(5 - 7) = 2.
MATHEMATICA
Array[Abs[First@ # - Last@ #] &@ IntegerDigits@ # &, 106] (* Michael De Vlieger, Oct 15 2018 *)
PROG
(PARI) a(n) = my(digs = digits(n)); abs(digs[1] - digs[#digs]); \\ Michel Marcus, Sep 27 2013
(PARI) apply( {A040163(n)=abs(n\10^logint(n+!n, 10)-n%10)}, [0..111]) \\ M. F. Hasler, Apr 22 2024
(Python) for n in range(1, 51): print(abs(int(str(n)[0])-int(str(n)[-1]))) # David F. Marrs, Oct 14 2018
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved