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A079823
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Consider the triangle shown below; sequence contains the concatenation of numbers read at a 45-degree angle upwards with horizontal beginning with the first term of a row.
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2
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1, 2, 43, 75, 1186, 16129, 22171310, 29231814, 3730241915, 4638312520, 564739322621, 675748403327, 79685849413428, 92806959504235, 10693817060514336, 121107948271615244, 137122108958372625345, 1541381231099684736354, 1721551391241109785746455
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listen;
history;
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internal format)
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OFFSET
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1,2
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COMMENTS
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1
2 3
4 5 6
7 8 9 10
11 12 13 14 15
16 17 18 19 20 21
...
a(n) also is the concatenation of the terms of the n-th row of A056536. - Michel Marcus, Dec 14 2023
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LINKS
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MAPLE
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read("transforms"):
A079823aux := proc(n, k)
end proc:
local L, k, n0 ;
n0 := n-1 ;
L := [] ;
for k from 0 do
if k > n0-k then
break;
end if;
L := [op(L), A079823aux(n0-k, k)] ;
end do:
digcatL(L) ;
# second Maple program:
T:= (i, j)-> i*(i-1)/2+j:
a:= n-> parse(cat(seq(T(n-j, j+1), j=0..(n-1)/2))):
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MATHEMATICA
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Table[FromDigits[Join@@IntegerDigits[Table[Binomial[n-k+1, 2] + k, {k, Ceiling[n/2]}]]], {n, 30}] (* G. C. Greubel, Dec 13 2023 *)
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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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More terms from Jason D. W. Taff (jtaff(AT)jburroughs.org), Oct 31 2003
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STATUS
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approved
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