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URL: https://oeis.org/A356761

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A356761
a(n) = L(2*L(n)) + L(2*L(n+1)), where L(n) is the n-th Lucas number (A000032).
2
10, 21, 65, 890, 40446, 33424885, 1322190707485, 44140596372269298846, 58360810951947188228658239895890, 2576080923024092500207469693559464507701547824744865, 150342171745412969401059031474740559845525757221446054521410222913066501974929718621
OFFSET
0,1
LINKS
Hideyuki Ohtsuka, Problem H-901, Advanced Problems and Solutions, The Fibonacci Quarterly, Vol. 60, No. 3 (2022), p. 281.
FORMULA
a(n) = A000032(2*A000032(n)) + A000032(2*A000032(n+1)).
Sum_{n>=0} (-1)^n/a(n) = 1/15 (Ohtsuka, 2022).
MATHEMATICA
a[n_] := LucasL[2*LucasL[n]] + LucasL[2*LucasL[n + 1]]; Array[a, 11, 0]
CROSSREFS
Sequence in context: A045973 A095679 A095192 * A096564 A041196 A082669
KEYWORD
nonn
AUTHOR
Amiram Eldar, Aug 26 2022
STATUS
approved