a(n) is the total number of pentagrams in a variant of pentagram fractal after n iterations.

Terms

a(0) =1a(1) =6a(2) =11a(3) =16a(4) =41a(5) =106a(6) =211a(7) =416a(8) =941a(9) =2106a(10) =4411a(11) =9316a(12) =20341a(13) =44106a(14) =94111a(15) =201716a(16) =435741a(17) =938606a(18) =2014311a(19) =4330116a(20) =9324641a(21) =20060606a(22) =43122511a(23) =92747016a(24) =199552041a(25) =429222606a(26) =923076211a(27) =1985467416a(28) =4270895441a(29) =9186237106