20617

Appears in sequences

• [ sqrt(3/2)^n ].at n=49A014215
• Numbers n>1 with the property that the decimal expansion of n is a permutation of the digits of the decimal expansion of phi(n) and the ratio n/phi(n) is a new record low value.at n=5A102018
• Numbers k such that the decimal digits of phi(k) are a permutation of those of k.at n=26A115921
• Triangle read by rows based on the Stirling numbers S1: t(n,m)=Sum[(-1)^(n + 1)* StirlingS1[n, j]*(k + 1 - j)^(n - 1), {j, 0, k + 1}].at n=12A152918
• a(n) = numerator of fraction whose decimal representation is (n).(1)(2)(3)...(n-1)(n).at n=3A172495
• 50k^2-20k-23 interleaved with 50k^2+30k+17 for k=>0.at n=41A217894
• a(n) = 1 + a(n-1) + a(n-2) + a(n-3) if n>=4; a(1) = a(2) = a(3) = 1.at n=17A248098
• Numbers k such that k![14]-2 is prime, where k![14] is the fourteen-fold multifactorial.at n=59A284190
• Composite hypotenuses of primitive Pythagorean triangles (A120961) that are not circumdiameters of non-Pythagorean primitive Heronian triangles (A285579).at n=26A329148