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A265843
Number of moves for the prime winding graph to have a zero x coordinate value.
2
1, 2, 6, 12, 18, 24, 36, 42, 48, 1150, 1154, 1180, 1188, 1206, 1240, 1268, 1688, 1970, 1982, 2016, 2028, 2040, 2194, 3270, 3300, 3308, 3346, 3360, 3372, 3390, 3408, 3438, 3480, 3510, 3518, 3554, 3562, 4042, 4542, 4554, 4574, 5136, 5164, 5174
OFFSET
1,2
COMMENTS
Define the prime winding graph as follows: Starting at (0,0) draw a straight line up the y-axis until the first prime is attained. Once the first prime is attained draw a straight line 90 degrees to the left until the second prime is attained. When the second prime is attained draw a straight line 90 degrees to the left until the third prime is attained. Repeat this process for all primes up to a specified number. The above sequence represents the number of moves required for the x coordinate to be equal to zero, where one move is equal to a line of length 1.
PROG
(PARI) lista(nn) = {x = 0; y = 0; dir = 1; for (n=1, nn, x += round(cos(dir*Pi/2)); y += round(sin(dir*Pi/2)); if (!x, print1(n, ", ")); if (isprime(n), dir ++); dir = dir % 4; ); } \\ Michel Marcus, Dec 17 2015
CROSSREFS
Sequence in context: A304450 A085345 A348774 * A276829 A032371 A162802
KEYWORD
nonn
AUTHOR
Gregory Whittaker, Dec 16 2015
STATUS
approved