40447

Appears in sequences

• Engel expansion of log(2).at n=8A059180
• Number of gap-free compositions of n into distinct parts, cf. A107428.at n=59A107461
• Place n points on each of the three sides of a triangle, 3n points in all; a(n) = number of nondegenerate triangles that can be constructed using these points (plus the 3 original vertices) as vertices.at n=20A130748
• Quadruple lucky numbers (lower terms). Numbers n such that n, n+2, n+6, n+8 are all Lucky numbers.at n=30A139783
• Numbers to which Mersenne primes 2^p-1 can be congruent mod k! (for k > 1).at n=11A145038
• Numbers that can be written using its own digits in order and by using addition and factorial operators.at n=20A195670
• a(n) = (5/128)*n^4*(n mod 2) + (((-5/128)*n^4*(n mod 2) - 26) mod n) + n^3 (n > 0).at n=26A294264
• Number of essentially parallel oriented series-parallel networks with n elements and without unit elements in parallel.at n=16A339155
• Centered heptagonal numbers which are semiprime.at n=39A381960