21446

Appears in sequences

• Triangle read by rows: T(n,k) is the number of paths in the first quadrant from (0,0) to (n,0), consisting of steps U=(1,1), D=(1,-1), h=(1,0) and H=(2,0), having k doublerises (i.e., UU's) (0 <= k <= floor(n/2) - 1 for n >= 2).at n=33A132279
• a(n) = 81*n^2 - 118*n + 43.at n=17A156677
• Greatest integer k such that k/2^n < phi^2, where phi = (1+sqrt(5))/2 = golden ratio.at n=13A293319
• Sum of the largest parts of the partitions of n into 9 squarefree parts.at n=46A326532
• The second smallest k such that A003415(k) == A276086(k) mod A002110(n), or -1 if no such k exists, where A003415 is the arithmetic derivative, A276086 is the primorial base exp-function, and A002110 gives the n-th primorial.at n=5A373603
• Numbers k such that primorial base expansion of A276086(k) has the primorial base expansion of A003415(k) as its suffix, where A003415 is the arithmetic derivative, and A276086 is the primorial base exp-function.at n=20A383933
• Number of fundamentally different graceful labelings of the n-pan graph.at n=10A387804