733008101376
domain: N
Appears in sequences
- a(n) = 2^(n-1)*(2^n - (-1)^n)/3.at n=21A003683
- Starting a priori with the fraction 1/1, the denominators of fractions built according to the rule: add top and bottom to get the new bottom, add top and 9 times the bottom to get the new top.at n=19A110953
- (A192466)/2.at n=20A192467
- Smallest pentagonal number with n prime factors (counted with multiplicity).at n=23A209049
- Expansion of Sum_{n>=0} (-4)^n * (2*4^n + 1)/3 * x^(n*(n+1)/2).at n=55A370018