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To get a(n+1), add to a(n) the product of the two closest digits to the comma printed before a(n); start with a(1)=a(2)=1.
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%I #8 Dec 15 2020 09:10:20

%S 1,1,2,4,12,16,18,24,40,56,56,86,134,140,144,144,148,152,160,162,162,

%T 164,166,170,176,176,182,188,190,198,198,206,222,234,238,246,262,274,

%U 278,286,302,320,326,326,344,362,374,380,392,392,398,404

%N To get a(n+1), add to a(n) the product of the two closest digits to the comma printed before a(n); start with a(1)=a(2)=1.

%C a(n+1) = a(n) + prod(the least significant digit of a(n-1), the most significant digit of a(n)).

%C From _Zak Seidov_, Oct 28 2010: (Start)

%C Starting with a(57701) all terms = 500040.

%C Apparently the sequence ends with constant terms for any initial terms a(1),a(2). (End)

%H Eric Angelini, <a href="http://www.cetteadressecomportecinquantesignes.com/AddProduct.htm">Add to a(n) a product of digits</a>

%H Eric Angelini, <a href="/A171943/a171943.pdf">Add to a(n) a product of digits</a> [Cached copy, with permission]

%K nonn,base

%O 1,3

%A _Eric Angelini_, Sep 25 2010