Sum of squares of heptanacci numbers (Fibonacci 7-step numbers).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =1a(7) =2a(8) =6a(9) =22a(10) =86a(11) =342a(12) =1366a(13) =5462a(14) =21591a(15) =85600a(16) =339616a(17) =1347632a(18) =5347632a(19) =21219888a(20) =84199984a(21) =334092848a(22) =1325649969a(23) =5260075594a(24) =20871578510a(25) =82816815054a(26) =328610657230