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 A242877 Number of points of norm <= n in square lattice which can be built as entire powers of points of the square lattice seen as image of the complex plane C* (excluding (0,0)). 1
 4, 6, 10, 12, 16, 20, 20, 24, 26, 30, 30, 42, 42, 46, 46, 48, 52, 52, 54, 58, 58, 58, 62, 62, 68, 70, 76, 76, 78, 80, 80, 92, 92, 96, 96, 98, 98, 102, 102, 106, 110, 110, 110, 110 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Martin Y. Champel, Table of n, a(n) for n = 1..10000 EXAMPLE for n=1, a(1)=4 as (1,0),(0,1),(-1,0),(0,-1) are powers of (1,0), (0,-1),(0,1) and (0,1) respectively powered by 2,3,2 and 3. for n=2, a(2)=6 as in addition of the 4 previous points can be found 2 points (0,2) and (0,-2) built as (1,1)^2 and (1,-1)^2. for n=3, a(3)=10 as in addition of the 6 previous points can be found 4 points (2,2), (2,-2), (-2,-2) and (-2,2) built as (-1,1)^3, (-1,-1)^3, (1,-1)^3 and (1,1)^3 respectively. PROG (Python) from math import * i0=complex(1, 0) i1=complex(0, 1) f0={0, i0, i1, -i0, -i1} def A242877(n): ....if n==0: return 0 ....if n==1: return 4 ....f0={0, i0, i1, -i0, -i1} ....k=2 ....while True: ........ro=n**(1/k) ........if ro

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Last modified June 2 11:35 EDT 2020. Contains 334771 sequences. (Running on oeis4.)