cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A033647 Base 10 digital convolution sequence.

Original entry on oeis.org

1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 40320, 403200, 846720, 2943360, 12620160, 66044160, 408885120, 2928240000, 23834805120, 217441486080, 47669610240, 482552582400, 1060444385280, 4146438320640, 18706642053120, 101826086906880, 648369805547520
Offset: 0

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Examples

			Suppose base = 3 and a(0)..a(13) are 1 1 2 1 3 7 6 20 52 6 26 104 32 162. In base 3, 14 = 112, so we convolve the last three terms with 1, 1, 2 to obtain 104*1+32*1+162*2 = 460.
		

Crossrefs

Programs

  • Maple
    a:= proc(n) option remember; `if`(n=0, 1, (l->
          add(l[i]*a(n-i), i=1..nops(l)))(convert(n, base, 10)))
        end:
    seq(a(n), n=0..33);  # Alois P. Heinz, Apr 14 2021