OFFSET
1,5
COMMENTS
Partial sums of number of positive knots with n crossings. The subsequence of distinct primes in this partial sum begins: 2, 3, 5, 17, 43.
FORMULA
a(n) = SUM[i=1..n] A018891(i).
EXAMPLE
a(15) = 0 + 0 + 1 + 0 + 1 + 0 + 1 + 1 + 1 + 3 + 2 + 7 + 9 + 17 + 47 = 90.
CROSSREFS
KEYWORD
nonn
AUTHOR
Jonathan Vos Post, Apr 19 2010
STATUS
approved