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A033930
Base 10 digital convolution sequence.
3
1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 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
0,3
COMMENTS
Differs from A007953 at n=0, 101-109, 111-119 etc. [R. J. Mathar, Oct 20 2008]
LINKS
FORMULA
For example, a(837) = 8*a(2)+3*a(1)+7*a(0).
MATHEMATICA
a = {1}; Do[AppendTo[a, ListConvolve[Reverse@ Take[a, Length@ #], #][[1]] &@ IntegerDigits@ n], {n, 10^3}]; a (* Michael De Vlieger, Feb 12 2017 *)
PROG
(PARI) a(n) = if (!n, 1, my(d = digits(n)); sum(i=1, #d, d[i]*a(#d-i))); \\ Michel Marcus, Sep 13 2014
CROSSREFS
Sequence in context: A177274 A349251 A131650 * A076314 A007953 A080463
KEYWORD
nonn,base
STATUS
approved