29616

Appears in sequences

• Numbers k such that sigma(phi(k)) = phi(sigma(k)).at n=14A033632
• Integers k such that k*28*c + 1 is prime for c = 1, 2, 4, 7 and 14.at n=15A067199
• Numbers k such that phi(2*sigma(k)) = 2*sigma(phi(k)).at n=17A067709
• Numbers k such that sigma(phi(k)) divides phi(sigma(k)).at n=25A073858
• Numbers k such that sigma(phi(k)) == phi(sigma(k)) (mod k), that is, A033632(k)/k is an integer.at n=16A092584
• Let P(A) be the power set of an n-element set A. Then a(n) = the number of pairs of elements {x,y} of P(A) for which either 0) x and y are intersecting but for which x is not a subset of y and y is not a subset of x, or 1) x and y are intersecting and for which either x is a proper subset of y or y is a proper subset of x, or 2) x = y.at n=8A134064
• Number of permutations of floor(i*8/3), i=0..n-1, with all sums of 4 adjacent terms unique.at n=7A152343
• a(n) = n*A007504(n)/2 = n*(sum of first n primes)/2.at n=32A156778
• Number of -n..n arrays x(0..2) of 3 elements with nonzero sum and with zero through 2 differences all nonzero.at n=15A200166
• x-values in the solution to x^2 - 13y^2 = 108.at n=14A228205
• Number of monohedral disk tilings of type C^t_{3,n}.at n=26A296361
• Expansion of (1/x) * Series_Reversion( x * (1/(1 + x) - x^2)^2 ).at n=7A379080