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A071938
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Binomial(max(n,R(n)),min(n,R(n))) where R(n) is the reversal of n.
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1
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1, 1, 1, 1, 1, 1, 1, 1, 1, 10, 1, 293930, 206253075, 35240152720, 3188675231420, 202802465047245, 10358022441395860, 456703981505085600, 18150420051920130975, 190, 293930, 1, 28048800, 353697121050
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OFFSET
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1,10
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COMMENTS
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a(n) = Binomial(n,reverse(n)) if n >= reverse(n); = Binomial(reverse(n),n) if n < reverse(n).
a(n) = 1 if n is a palindrome. a(n) = n if n = 10^k. - Amarnath Murthy, Jul 14 2005
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LINKS
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EXAMPLE
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a(10) = binomial(10,1) = 10, a(11) = 1, a(12) = binomial(21,12) = 293930.
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MAPLE
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R:=proc(n) local nn, nnn: nn:=convert(n, base, 10): add(nn[nops(nn)+1-j]*10^(j-1), j=1..nops(nn)) end: seq(binomial(max(n, R(n)), min(n, R(n))), n=1..27); # Emeric Deutsch, Jul 16 2005
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MATHEMATICA
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bmm[n_]:=Module[{ir=IntegerReverse[n]}, Binomial[Max[n, ir], Min[n, ir]]]; Array[ bmm, 30] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Dec 13 2020 *)
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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