OFFSET
0,12
COMMENTS
More than the usual number of terms are shown in order to distinguish this from related sequences.
LINKS
Michael De Vlieger, Table of n, a(n) for n = 0..10000
FORMULA
From Alois P. Heinz, Apr 19 2019: (Start)
EXAMPLE
For n<10 there is only one decimal digit so a(n)=0.
a(102) = 1+0 + 1+2 + 0+2 = 6.
MAPLE
a:= n-> (d-> (nops(d)-1)*add(i, i=d))(convert(n, base, 10)):
seq(a(n), n=0..120); # Alois P. Heinz, Apr 19 2019
MATHEMATICA
Array[Total@ Flatten@ Subsets[IntegerDigits@ #, {2}] &, 103, 0] (* Michael De Vlieger, Apr 19 2019 *)
CROSSREFS
KEYWORD
AUTHOR
N. J. A. Sloane, Apr 19 2019
STATUS
approved