Search: id:A128019 Results 1-1 of 1 results found. %I A128019 %S A128019 1,3,3,9,9,27,27,81,81,243,243,729,729,2187,2187,6561,6561,19683,19683, %T A128019 59049,59049,177147,177147,531441,531441,1594323,1594323,4782969, %U A128019 4782969,14348907,14348907,43046721 %V A128019 1,-3,-3,9,9,-27,-27,81,81,-243,-243,729,729,-2187,-2187,6561,6561,-19683, -19683,59049, %W A128019 59049,-177147,-177147,531441,531441,-1594323,-1594323,4782969,4782969, -14348907, %X A128019 -14348907,43046721 %N A128019 Expansion of (1-3x)/(1+3x^2). %C A128019 Binomial transform is A128018. %F A128019 a(n)=3^floor((n+1)/2)*(-1)^C(n+1,2); %Y A128019 Cf. A108411. %Y A128019 Sequence in context: A147510 A146474 A145957 this_sequence A108411 A056449 A162436 %Y A128019 Adjacent sequences: A128016 A128017 A128018 this_sequence A128020 A128021 A128022 %K A128019 easy,sign %O A128019 0,2 %A A128019 Paul Barry (pbarry(AT)wit.ie), Feb 11 2007 Search completed in 0.001 seconds