25161728

Appears in sequences

• Number of occurrences of pattern 2-1 after n iterations of morphism A007413.at n=12A093357
• Numbers k such that phi(k) + sigma(k) = (5/2)*k.at n=8A115747
• Near-perfect numbers (A181595) of the form 2^(t-1)*(2^t-2^k-1), where 2^t-2^k-1 is prime, k>=1, t>k.at n=29A181701
• Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 22", based on the 5-celled von Neumann neighborhood.at n=12A269716
• Three-column array pPT read by rows: subsequence of primitive Pythagorean triples (x, y, z) with x = A153893^2 - A000079^2, y = 2*A153893*A000079, z = A153893^2 + A000079^2, ordered by increasing z.at n=34A334638