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A095661
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Fifth column (m=4) of (1,3)-Pascal triangle A095660.
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1
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3, 13, 35, 75, 140, 238, 378, 570, 825, 1155, 1573, 2093, 2730, 3500, 4420, 5508, 6783, 8265, 9975, 11935, 14168, 16698, 19550, 22750, 26325, 30303, 34713, 39585, 44950, 50840, 57288, 64328, 71995, 80325, 89355, 99123, 109668, 121030, 133250, 146370
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| If Y is a 3-subset of an n-set X then, for n>=6, a(n-6) is the number of 4-subsets of X having at most one element in common with Y. - Milan R. Janjic (agnus(AT)blic.net), Nov 23 2007
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FORMULA
| G.f.: (3-2*x)/(1-x)^5.
a(n)= (n+12)*binomial(n+3, 3)/4 = 3*b(n)-2*b(n-1), with b(n):=binomial(n+4, 4); cf. A000332.
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MATHEMATICA
| s1=s2=s3=s4=0; lst={}; Do[a=n+(n+2); s1+=a; s2+=s1; s3+=s2; s4+=s3; AppendTo[lst, s3/2], {n, 2, 5!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Apr 04 2009]
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CROSSREFS
| Sequence in context: A016061 A154154 A137976 * A058214 A108480 A146741
Adjacent sequences: A095658 A095659 A095660 * A095662 A095663 A095664
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KEYWORD
| nonn,easy
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AUTHOR
| Wolfdieter Lang (wolfdieter.lang_AT_physik_DOT_uni-karlsruhe_DOT_de), Jun 11 2004
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