A265843 - OEIS

%I #28 Jun 23 2022 20:33:28

%S 1,2,6,12,18,24,36,42,48,1150,1154,1180,1188,1206,1240,1268,1688,1970,

%T 1982,2016,2028,2040,2194,3270,3300,3308,3346,3360,3372,3390,3408,

%U 3438,3480,3510,3518,3554,3562,4042,4542,4554,4574,5136,5164,5174

%N Number of moves for the prime winding graph to have a zero x coordinate value.

%C 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.

%H Gregory Whittaker, <a href="/A265843/a265843_2.png">Prime winding graph</a>

%H Gregory Whittaker, <a href="/A265843/a265843_4.js.txt">JavaScript code for prime winding graphK</a>

%o (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

%K nonn

%O 1,2

%A _Gregory Whittaker_, Dec 16 2015