Search: id:A091344 Results 1-1 of 1 results found. %I A091344 %S A091344 0,1,7,31,115,391,1267,3991,12355,37831,115027,348151,1050595,3164071, %T A091344 9516787,28599511,85896835,257887111,774054547,2322950071,6970423075, %U A091344 20914414951,62749536307,188261191831,564808741315,1694476555591 %N A091344 a(n) = 2*3^n-3*2^n+1. %C A091344 Starting with offset 1 = binomial transform of A068193: (1, 6, 18, 42, 90,...) and double binomial transform of (1, 5, 7, 5, 7, 5,...). [From Gary W. Adamson (qntmpkt(AT)yahoo.com), Jan 13 2009] %D A091344 Ballot, Christian and Luca, Florian, Prime factors of a^f(n)-1 with an irreducible polynomial f(x). New York J. Math. 12 (2006), 39-45 (electronic). %D A091344 Ballot, Christian and Luca, Florian, Common prime factors of a^n-b and c^n-d. Unif. Distrib. Theory 2 (2007), no. 2, 19-34 (electronic). %H A091344 Index entries for sequences related to linear recurrences with constant coefficients %F A091344 a(n)=Sum(i!*i^2*Stirling2(n,i)*(-1)^(n-i), i=1,..,n) %F A091344 a_n = 6a_{n-1} - 11a_{n-2} + 6a_{n-3}, g.f.: x(1+x)/(1-x)(2-x)(3-x)). - Christian Ballot via R. K. Guy, Jan 13 2009 %p A091344 a:=n->sum((3^(n-j-1)-2^(n-2-j))*12, j=0..n): seq(a(n), n=-1..24); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Feb 11 2007 %p A091344 with (combinat):a:=n->stirling2(n,3)+stirling2(n+1,3): seq(a(n), n=1..26); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Oct 07 2007 %t A091344 Table[Sum[i!i^2 StirlingS2[n, i](-1)^(n - i), {i, 1, n}], {n, 0, 30}] %Y A091344 A068293 [From Gary W. Adamson (qntmpkt(AT)yahoo.com), Jan 13 2009] %Y A091344 Sequence in context: A055580 A097786 A006458 this_sequence A032197 A114289 A147597 %Y A091344 Adjacent sequences: A091341 A091342 A091343 this_sequence A091345 A091346 A091347 %K A091344 easy,nonn %O A091344 0,3 %A A091344 Mario Catalani (mario.catalani(AT)unito.it), Jan 01 2004 %E A091344 Edited by N. J. A. Sloane (njas(AT)research.att.com), Jan 13 2009 at the suggestion of R. K. Guy. The concise definition was provided by Vladeta Jovovic (vladeta(AT)eunet.rs), Jan 01 2004. Search completed in 0.001 seconds