19405

Appears in sequences

• Sums of 5 distinct powers of 5.at n=17A038477
• Third row of Pascal-(1,5,1) array A081580.at n=33A081589
• a(1)=1, a(2)=2; for n >= 2, a(n+1) = a(n) + sum of prime factors of a(n).at n=41A096461
• Least k such that prime(n)^2 divides binomial(2k,k).at n=44A110494
• Number of partitions of n having exactly 1 part that appears exactly once.at n=47A116596
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (0, 0, -1), (0, 1, -1), (1, 0, -1), (1, 1, 1)}.at n=8A149633
• a(n) = 44*n^2 + 1.at n=21A158630
• a(n+1) is the sum of a(n) and the prime factors of a(n), counted with multiplicity. Start with a(0) = 3.at n=25A192896
• Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^4>x^4+y^4.at n=40A211653
• Numbers k^2 + (k+1)^2 that can be expressed as a sum of two squares in exactly one other way.at n=42A239527
• Number of partitions of n with difference -5 between the number of odd parts and the number of even parts, both counted without multiplicity.at n=44A242687
• Composites whose prime factorization in base 8 is an anagram of the number in base 8.at n=10A260052
• Relative of Hofstadter Q-sequence: a(n) = max(0, n+19395) for n <= 0; a(n) = a(n-a(n-1)) + a(n-a(n-2)) + a(n-a(n-3)) for n > 0.at n=13A283886
• Triangle read by rows: T(n,k) number of ways of partitioning the (n+3)-element multiset {1,1,1,1,2,3,...,n} into exactly k nonempty parts, n >= 0 and 1 <= k <= n + 3.at n=70A291118
• Number of self-avoiding polygons with perimeter n and sides = 1 that have vertex angles from the set 0, +-Pi/5, +-2*Pi/5, +-3*Pi/5, +-4*Pi/5, not counting rotations and reflections as distinct.at n=10A316200
• a(n) = (4*n^3 + 30*n^2 + 50*n)/3 + 1.at n=22A323218
• Number of partitions p of n such that min(p) <= (number of parts of p) <= max(p).at n=39A325343
• a(0) = 0; a(n) = n^3 - (1/n) * Sum_{k=1..n-1} binomial(n,k)^2 * (n-k)^3 * k * a(k).at n=5A337825
• Fold a square sheet of paper alternately vertically to the left and horizontally downwards; after each fold, draw a line along each inward crease; after n folds, the largest region in the resulting graph occupies a(n)/2^n of the whole sheet.at n=16A342764
• Centered square numbers which are semiprime.at n=44A371016