A062876 - OEIS

%I #40 Aug 03 2024 07:16:30

%S 4,12,20,28,44,52,68,76,92,116,124,148,164,172,188,212,236,244,268,

%T 284,292,316,332,356,388,404,412,428,436,452,508,524,548,556,596,604,

%U 628,652,668,692,716,724,764,772,788,796,844,892,908,916,932,956,964

%N Numbers of lattice points corresponding to incrementally largest circle radii in A062875.

%C For n = 1 and n >= 3, a(n) is the smallest nonsquarefree number divisible by prime(n). - _David James Sycamore_, Jun 15 2024

%H Ray Chandler, <a href="/A062876/b062876.txt">Table of n, a(n) for n = 1..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/CircleLatticePoints.html">Circle Lattice Points</a>

%F a(n) = A017113(A111333(n)-1) = 8*A111333(n) - 4.

%F For n >= 2 a(n) = 4*A000040(n) (a term in A013929). - _David James Sycamore_, Jun 15 2024

%t Join[{4}, Table[4 Prime[n], {n, 2, 50}]] (* _Vincenzo Librandi_, May 08 2015 *)

%o (Magma) [4] cat [4*NthPrime(n): n in [2..60]]; // _Vincenzo Librandi_, May 08 2015

%o (PARI) a(n)=if(n>1,4*prime(n),4) \\ _Charles R Greathouse IV_, May 08 2015

%o (Python)

%o from sympy import prime

%o def A062876(n): return prime(n)<<2 if n>1 else 4 # _Chai Wah Wu_, Aug 02 2024

%Y Cf. A046112, A062875.

%Y Cf. A017113, A111333.

%Y Cf. A000040, A103929

%K easy,nonn

%O 1,1

%A _Eric W. Weisstein_

%E Edited and extended by _Ray Chandler_, Jan 05 2012