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A326178 Number of subsets of {1..n} whose product is equal to their sum. 4
0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Same as A001477 (the nonnegative integers) with 3 removed.

LINKS

Table of n, a(n) for n=0..66.

EXAMPLE

The a(1) = 1 through a(9) = 10 subsets:

  {1}  {1}  {1}      {1}      {1}      {1}      {1}      {1}      {1}

       {2}  {2}      {2}      {2}      {2}      {2}      {2}      {2}

            {3}      {3}      {3}      {3}      {3}      {3}      {3}

            {1,2,3}  {4}      {4}      {4}      {4}      {4}      {4}

                     {1,2,3}  {5}      {5}      {5}      {5}      {5}

                              {1,2,3}  {6}      {6}      {6}      {6}

                                       {1,2,3}  {7}      {7}      {7}

                                                {1,2,3}  {8}      {8}

                                                         {1,2,3}  {9}

                                                                  {1,2,3}

MATHEMATICA

Table[Length[Select[Subsets[Range[n]], Times@@#==Plus@@#&]], {n, 0, 10}]

CROSSREFS

Cf. A053632, A057567, A057568, A063865, A301987, A326156, A326158, A326179, A326180.

Sequence in context: A196252 A004722 A094798 * A162880 A083792 A083794

Adjacent sequences:  A326175 A326176 A326177 * A326179 A326180 A326181

KEYWORD

nonn,dumb

AUTHOR

Gus Wiseman, Jun 13 2019

STATUS

approved

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Last modified October 18 18:56 EDT 2019. Contains 328197 sequences. (Running on oeis4.)