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A073152 Triangle of numbers relating two simple context-free grammars (A052709 and A052705). +0
2
1, 1, 2, 3, 4, 7, 9, 12, 15, 24, 31, 40, 49, 58, 89, 113, 144, 171, 198, 229, 342, 431, 544, 637, 718, 811, 924, 1355, 1697, 2128, 2467, 2746, 3025, 3364, 3795, 5492, 6847, 8544, 9837, 10854, 11815, 12832, 14125, 15822, 22669, 28161 (list; table; graph; listen)
OFFSET

0,3

COMMENT

Sequence A052705 is the convolution of A052709.

REFERENCES

D. Merlini, D. G. Rogers, R. Sprugnoli and M. C. Verri, On some alternative characterizations of Riordan arrays, Canad. J.

LINKS

D. Merlini, D. G. Rogers, R. Sprugnoli and M. C. Verri, On some alternative characterizations of Riordan arrays, Canad. J.

FORMULA

Triangle {a(n, k), n >= 0, 0<=k<=n} defined by: a(0, 0)=1, a(n, 0)=A052709(n+1), a(n, n)=A052705(n+2), a(n, 0)=a(n-1, n-1) + a(n-2, n-2), a(n, k)=sum{j=0..k} A052709(j+1) * a(n-j, 0).

EXAMPLE

a(5,0)=a(3,3)+a(4,4)=24+89=113. a(5,3)=1*a(5,0)+1*a(4,0)+3*a(3,0)+9*a(2,0)=1*113+1*31+3*9+9*3=198. Rows: {1}; {1,2}; {3,4,7}; {9,12,15,24}; {31,40,49,58,89}; {113,144,171,198,229,342}; {431,544,637,718,811,924,1355}; {1697,2128,2467,2746,3025,3364,3795,5492}

CROSSREFS

Cf. A052709, A052705.

Adjacent sequences: A073149 A073150 A073151 this_sequence A073153 A073154 A073155

Sequence in context: A084913 A117450 A132381 this_sequence A051061 A005576 A129373

KEYWORD

easy,nonn,tabl

AUTHOR

Paul D. Hanna (pauldhanna(AT)juno.com), Jul 29 2002

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Last modified October 13 20:18 EDT 2008. Contains 145016 sequences.


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