61697

Appears in sequences

• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (Lucas numbers), t = (composite numbers).at n=27A025091
• Cototient of 2^n + 1.at n=20A053286
• Number of ordered partitions of partitions.at n=12A055887
• a(n) is the smallest number which can be represented as the sum of n distinct nonzero n-gonal pyramidal numbers in exactly n ways, or -1 if no such number exists.at n=11A350397