103320

Appears in sequences

• a(n) = floor( n*(n-1)*(n-2)*(n-3)/26 ).at n=42A011936
• Inflation orbit counts.at n=23A031367
• Number of periodic palindromes using exactly six different symbols.at n=13A056492
• Number of primitive (period n) periodic palindromes using exactly six different symbols.at n=13A056502
• Integers y such that for some integer x we have uphi(x) = uphi(y) = x-y, where uphi(n) = A047994(n) is the unitary totient function: If n = Product p_i^e_i, uphi(n) = Product (p_i^e_i - 1).at n=16A067741
• The triangle T_2(n, m), where T_2(n, m) is the number of surjective multi-valued functions from {1, 1, 2, 3, ..., n-1} to {1, 2, 3, ..., m} by rows (n >= 1, 1 <= m <= n).at n=33A172106
• Numbers n for which the terms of the multiplicative sequence {n^2/A049417(n)} are integers.at n=41A185288
• Numbers with prime factorization p*q*r*s^2*t^3 (where p, q, r, s, t are distinct primes).at n=33A190111
• Triangle T(n,k) represents the coefficients of (x^18*d/dx)^n, where n=1,2,3,....at n=33A223520
• a(n) = (Product_{i=0..4}(i*n+2) - Product_{i=0..4}(-i*n-1))/(4*n+3).at n=17A274119
• Triangle read by rows: T(n,k) is the number of achiral loops (necklaces or bracelets) of length n using exactly k different colors.at n=60A305540
• Expansion of e.g.f. Product_{k>=0} 1/(1 - x^(2^k)/2^k).at n=8A306947
• Numbers k such that N = k^6 is a twin rank (cf. A002822: 6N +- 1 are twin primes).at n=25A326236
• T(n,k) = [0<k<=n] * n*(T(n-1,k-1)+T(n-1,k)) + [k=0 and n>=0]; triangle T(n,k), n >= 0, 0 <= k <= n, read by rows.at n=33A326659
• Irregular triangle read by rows: T(n,k) is the number of primitive (period n) periodic palindromes using exactly k different symbols, 1 <= k <= 1 + floor(n/2).at n=60A327878
• a(n) is the smallest number k >= 1 with exactly n divisors d, for which sigma(k) is divisible by d*sigma(d).at n=27A344103
• a(n) = sqrt((x^2 - y^2)*x*y/c) where x is A364108(n), y is A364109(n) and c is A006991(n).at n=11A364110
• Expansion of e.g.f. 1 / (1 + x * log(1 - x))^3.at n=7A375672
• a(n) = Product_{k=0..n} (k^5 + n).at n=3A375842
• Define f(x) = abs(1-1/x) and sequence {b(m)} such that b(m+1) = f(b(m)). a(n) is the number of initial values b(1) such that {b(m)}'s period has length n.at n=23A378853