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A195851
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Column 7 of array A195825. Also column 1 of triangle A195841. Also 1 together with the row sums of triangle A195841.
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14
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1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 4, 4, 4, 4, 4, 5, 7, 10, 12, 13, 13, 13, 13, 14, 16, 21, 27, 32, 34, 35, 35, 36, 38, 44, 54, 67, 77, 83, 85, 87, 89, 95, 107, 128, 152, 173, 185, 192, 196, 203, 216, 242, 281, 328, 367, 394, 409, 421, 436, 465
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,9
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COMMENTS
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Note that this sequence contains four plateaus: [1, 1, 1, 1, 1, 1, 1, 1], [4, 4, 4, 4, 4, 4], [13, 13, 13, 13], [35, 35]. For more information see A210843 and other sequences of this family. - Omar E. Pol, Jun 29 2012
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LINKS
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FORMULA
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G.f.: Product_{k>=1} 1/((1 - x^(9*k))*(1 - x^(9*k-1))*(1 - x^(9*k-8))). - Ilya Gutkovskiy, Aug 13 2017
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MAPLE
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(18*n*(n+1)+5*(2*n+1)*(-1)^n-5)/16 ;
end proc:
option remember;
local ks, a, j ;
0 ;
elif n <= 5 then
return 1;
elif k = 1 then
a := 0 ;
for j from 1 do
a := a+procname(n-1, j) ;
else
break;
end if;
end do;
return a;
else
(-1)^floor((k-1)/2)*procname(n-ks+1, 1) ;
end if;
end proc:
end proc:
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PROG
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(GWbasic)' A program with two A-numbers:
20 For n = 1 to 61: For j = 1 to n
40 Next j: Print a(n-1); : Next n
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CROSSREFS
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Cf. A000041, A001082, A006950, A036820, A057077, A195160, A195831, A195825, A195848, A195849, A195850, A195852, A196933, A210964, A211971.
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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