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A321164 Sum of distinct products b_1*b_2*...*b_n where 1<=b_i<=n. 1
1, 7, 90, 1441, 38325, 916714, 37830100, 1194352181, 45241845825, 1951734678972, 147430334155104, 5664495439368403, 528359397843879784, 30798685780200874044, 1774211038440007650672, 99969666291681633988821, 13249072759407029981640765, 847264606120975715873578180 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..18.

EXAMPLE

a(2) = 1 + 2 + 4 = 7.

a(3) = 1 + 2 + 3 + 4 + 6 + 8 + 9 + 12 + 18 + 27 = 90.

MAPLE

a:= proc(m) option remember; local b; b:=

      proc(n) option remember; `if`(n=0, {1},

        map(x-> seq(x*i, i=1..m), b(n-1)))

      end; forget(b); add(i, i=b(m))

    end:

seq(a(n), n=1..12);  # Alois P. Heinz, Jan 11 2019

CROSSREFS

Main diagonal of A321163.

Cf. A110713.

Sequence in context: A200832 A103064 A244849 * A243699 A007820 A306137

Adjacent sequences:  A321161 A321162 A321163 * A321165 A321166 A321167

KEYWORD

nonn

AUTHOR

Seiichi Manyama, Jan 10 2019

EXTENSIONS

a(15)-a(18) from Alois P. Heinz, Jan 11 2019

STATUS

approved

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Last modified October 21 14:52 EDT 2019. Contains 328301 sequences. (Running on oeis4.)