Search: id:A101514 Results 1-1 of 1 results found. %I A101514 %S A101514 1,1,2,7,35,236,2037,21695,277966,4198635,73558135,1475177880, %T A101514 33495959399,853167955357,24182881926558,757554068775721, %U A101514 26068954296880361,980202973852646786,40079727064364154465 %N A101514 Shifts one place left under the square binomial transform (A008459): a(0) = 1, a(n+1) = Sum_{k=0..n-1} C(n-1,k)^2*a(k). %C A101514 Equals the main diagonal of symmetric square array A101515 shift right. %e A101514 The binomial transform of the rows of the Hadamard product of this sequence %e A101514 with the rows of Pascal's triangle produces the symmetric square array %e A101514 A101515, in which the main diagonal equals this sequence shift left: %e A101514 BINOMIAL[1*1] = [_1,1,1,1,1,1,1,1,1,...], %e A101514 BINOMIAL[1*1,1*1] = [1,_2,3,4,5,6,7,8,9,...], %e A101514 BINOMIAL[1*1,1*2,2*1] = [1,3,_7,13,21,31,43,57,73,...], %e A101514 BINOMIAL[1*1,1*3,2*3,7*1] = [1,4,13,_35,77,146,249,393,...], %e A101514 BINOMIAL[1*1,1*4,2*6,7*4,35*1] = [1,5,21,77,_236,596,1290,...], %e A101514 BINOMIAL[1*1,1*5,2*10,7*10,35*5,236*1] = [1,6,31,146,596,_2037,...],... %e A101514 Thus the square binomial transform shifts this sequence one place left: %e A101514 a(5) = 236 = 1^2*(1) + 4^2*(1) + 6^2*(2) + 4^2*(7) + 1^2*(35), %e A101514 a(6) = 2037 = 1^2*(1) + 5^2*(1) + 10^2*(2) + 10^2*(7) + 5^2*(35) + 1^2*(236). %p A101514 a:= proc(n) option remember; local k; if n<=0 then 1 else add (binomial(n-1, k)^2 *a(k), k=0..n-1) fi end: seq (a(n), n=0..18); [From Alois P. Heinz (heinz(AT)hs-heilbronn.de), Sep 05 2008] %o A101514 (PARI) a(n)=if(n==0,1,sum(k=0,n-1,binomial(n-1,k)^2*a(k))) %Y A101514 Cf. A101515, A101516, A008459. %Y A101514 Sequence in context: A000154 A003713 A058129 this_sequence A111908 A060814 A129261 %Y A101514 Adjacent sequences: A101511 A101512 A101513 this_sequence A101515 A101516 A101517 %K A101514 nonn %O A101514 0,3 %A A101514 Paul D. Hanna (pauldhanna(AT)juno.com), Dec 06 2004 Search completed in 0.001 seconds