A062876 Numbers of lattice points corresponding to incrementally largest circle radii in A062875.

4, 12, 20, 28, 44, 52, 68, 76, 92, 116, 124, 148, 164, 172, 188, 212, 236, 244, 268, 284, 292, 316, 332, 356, 388, 404, 412, 428, 436, 452, 508, 524, 548, 556, 596, 604, 628, 652, 668, 692, 716, 724, 764, 772, 788, 796, 844, 892, 908, 916, 932, 956, 964

Offset: 1

Author

Eric W. Weisstein

Keywords

• easy
• nonn

Comments

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

Links

• Ray Chandler, Table of n, a(n) for n = 1..10000
• Eric Weisstein's World of Mathematics, Circle Lattice Points

Crossrefs

Cf. A046112, A062875.

Cf. A017113, A111333.

Cf. A000040, A103929

Programs

Magma

[4] cat [4*NthPrime(n): n in [2..60]]; // Vincenzo Librandi, May 08 2015

Mathematica

Join[{4}, Table[4 Prime[n], {n, 2, 50}]] (* Vincenzo Librandi, May 08 2015 *)

PARI

a(n)=if(n>1,4*prime(n),4) \\ Charles R Greathouse IV, May 08 2015

Python

from sympy import prime
def A062876(n): return prime(n)<<2 if n>1 else 4 # Chai Wah Wu, Aug 02 2024

Formula

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

For n >= 2 a(n) = 4*A000040(n) (a term in A013929). - David James Sycamore, Jun 15 2024

Extensions

Edited and extended by Ray Chandler, Jan 05 2012