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A203157
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(n-1)-st elementary symmetric function of the first n triangular numbers.
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1
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1, 4, 27, 288, 4500, 97200, 2778300, 101606400, 4629441600, 257191200000, 17116074360000, 1344389840640000, 123067686661920000, 12988374315396480000, 1565562975516540000000, 213751531590524928000000, 32817539834507780352000000
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OFFSET
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1,2
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LINKS
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Table of n, a(n) for n=1..17.
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EXAMPLE
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Let esf abbreviate "elementary symmetric function". Then
0th esf of {1}: 1
1st esf of {1,3}: 1+3=4
2nd esf of {1,3,6} is 1*3+1*6+3*6=27
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MATHEMATICA
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f[k_] := k (k + 1)/2; t[n_] := Table[f[k], {k, 1, n}]
a[n_] := SymmetricPolynomial[n - 1, t[n]]
Table[a[n], {n, 1, 22}] (* A203157 *)
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CROSSREFS
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Cf. A000217.
Sequence in context: A020558 A193467 A179494 * A119820 A159599 A221411
Adjacent sequences: A203154 A203155 A203156 * A203158 A203159 A203160
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KEYWORD
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nonn
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AUTHOR
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Clark Kimberling, Dec 29 2011
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STATUS
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approved
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