Search: id:A117809 Results 1-1 of 1 results found. %I A117809 %S A117809 2,7,3,26,13,7,96,48,24,12,362,181,91,46,23,1350,675,337,168,84,42,5042, %T A117809 2521,1261,631,316,158,79,18816,9408,4704,2352,1176,588,294,147,70226, 35113, %U A117809 17557,8779,4390,2195,1098,549,275,262086,131043,65521,32760,16380,8190, 4095 %V A117809 -2,7,3,-26,-13,-7,96,48,24,12,-362,-181,-91,-46,-23,1350,675,337,168, 84,42,-5042, %W A117809 -2521,-1261,-631,-316,-158,-79,18816,9408,4704,2352,1176,588,294,147, -70226,-35113, %X A117809 -17557,-8779,-4390,-2195,-1098,-549,-275,262086,131043,65521,32760,16380, 8190,4095 %N A117809 a(n,m) =Floor[N[(-2 + Sqrt[3])^n + (-2 - Sqrt[3])^n]/2^m]. %C A117809 A triangular prime alternating sign Binet like function. %e A117809 -2 %e A117809 7, 3 %e A117809 -26, -13,-7 %e A117809 96, 48, 24, 12 %e A117809 -362,-181, -91, -46, -23 %e A117809 1350, 675, 337, 168, 84, 42 %t A117809 f[n_, m_] = N[(-2 + Sqrt[3])^n + (-2 - Sqrt[3])^n]/2^m a = Table[Table[Floor[f[n, m]], {m, 1, n}], {n, 1, 10}] aa = Flatten[a] pp = Flatten[Table[If[PrimeQ[aa[[n]]], aa[[n]], {}], {n, 1, Length[aa]}]] Length[pp]/Length[aa] %Y A117809 Sequence in context: A138751 A112303 A089124 this_sequence A052091 A090276 A090564 %Y A117809 Adjacent sequences: A117806 A117807 A117808 this_sequence A117810 A117811 A117812 %K A117809 sign,tabl %O A117809 0,1 %A A117809 Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Apr 29 2006 Search completed in 0.001 seconds