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A085438
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a(n) = Sum_{i=1..n} C(i+1,2)^3.
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22
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1, 28, 244, 1244, 4619, 13880, 35832, 82488, 173613, 339988, 627484, 1102036, 1855607, 3013232, 4741232
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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REFERENCES
| Elisabeth Busser and Gilles Cohen, Neuro-Logies - "Chercher, jouer, trouver", La Recherche, April 1999, No. 319, page 97.
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FORMULA
| i=1_Sum_n [i+1_C_2]^3 = [ 90*n^7 +630*n^6 +1638*n^5 +1890*n^4+ 840*n^3 -48*n ]/7!
Sum_(i=1..n) C(i+1, 2)^3 = [ C(n+2, 3)/35 ]*[ 35 +210*C(n-1, 1) +399*C(n-1, 2) +315*C(n-1, 3) +90*C(n-1, 4) ]
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EXAMPLE
| 1=1_Sum_10 [1+1_C_2]^3 = [90*(10^7)+630*(10^6)+1638*(10^5)+1890*(10^4) +840*(10^3)-48*(10)]/5040 = 339988
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CROSSREFS
| Cf. A000292, A087127, A024166, A024166, A085439, A085440, A085441, A085442, A000332, A086020, A086021, A086022, A000389, A086023, A086024, A000579, A086025, A086026, A000580, A086027, A086028, A027555, A086029, A086030.
Sequence in context: A024015 A119544 A112797 * A188526 A092341 A042522
Adjacent sequences: A085435 A085436 A085437 * A085439 A085440 A085441
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KEYWORD
| easy,nonn
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AUTHOR
| Andre F. Labossiere (boronali(AT)laposte.net), Jun 30 2003
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