A193495 -id:A193495 - cp's OEIS frontend

A280108 Sum of odd divisors of Lucas(n).

1, 4, 1, 8, 12, 13, 30, 48, 20, 168, 200, 192, 522, 1128, 384, 2208, 3572, 4320, 9350, 17296, 6360, 54208, 64680, 52992, 186048, 361928, 115600, 826728, 1169400, 1377012, 3010350, 4876416, 1980400, 17256768, 23639040, 19906944, 54018522, 116538408

Offset: 1

Vincenzo Librandi, Jan 06 2017

nonn

Vincenzo Librandi, Table of n, a(n) for n = 1..300

Cf. A000032, A000593, A193495.

a[n_]:=Select[Divisors[LucasL[n]], OddQ]//Total;Table[a[n], {n, 1, 40}]

a(n) = A000593(A000032(n)).

A280728 Number of even divisors of Lucas(n).

Original entry on oeis.org

1, 0, 0, 2, 0, 0, 3, 0, 0, 4, 0, 0, 4, 0, 0, 8, 0, 0, 8, 0, 0, 8, 0, 0, 4, 0, 0, 8, 0, 0, 12, 0, 0, 8, 0, 0, 8, 0, 0, 16, 0, 0, 24, 0, 0, 64, 0, 0, 8, 0, 0, 16, 0, 0, 20, 0, 0, 16, 0, 0, 32, 0, 0, 64, 0, 0, 24, 0, 0, 32, 0, 0, 8, 0, 0, 128, 0, 0, 12, 0, 0

Offset: 0

Vincenzo Librandi, Jan 09 2017

nonn

Amiram Eldar, Table of n, a(n) for n = 0..1000

Cf. A000032, A183063, A193495.

a[n_]:=Block[{d=Divisors[LucasL[n]]}, Count[EvenQ[d], True]]; Table[a[n], {n, 0, 80}]

a(n) = A183063(A000032(n)).

Offset corrected by Amiram Eldar, Sep 03 2019

cp's OEIS Frontend

A280108 Sum of odd divisors of Lucas(n).

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