cp's OEIS Frontend

A160792 Vertex number of a rectangular spiral related to prime numbers. The distances between nearest edges of the spiral that are parallel to the initial edge are the prime numbers, while the distances between nearest edges perpendicular to the initial edge are all one.

%I A160792 #13 Feb 21 2019 13:50:32
%S A160792 0,1,3,5,10,13,23,27,44,49,77,83,124,131,189,197,274,283,383,393,522,
%T A160792 533,693,705,902,915,1153,1167,1448,1463,1791,1807,2188,2205,2645,
%U A160792 2663,3164,3183,3751,3771,4410,4431,5143,5165,5956,5979,6853,6877,7840,7865
%N A160792 Vertex number of a rectangular spiral related to prime numbers. The distances between nearest edges of the spiral that are parallel to the initial edge are the prime numbers, while the distances between nearest edges perpendicular to the initial edge are all one.
%C A160792 First differences give A160793. - _Omar E. Pol_, Oct 31 2011
%H A160792 Nathaniel Johnston, <a href="/A160792/b160792.txt">Table of n, a(n) for n = 0..5000</a>
%F A160792 a(2n) = a(2n-1) + Sum_{j=1..n} prime(j); a(2n+1) = a(2n) + n + 1 for n >= 1. - _Nathaniel Johnston_, Jun 16 2011
%p A160792 A160792 := proc(n) option remember: if(n<=1)then return n: fi: if(n mod 2 = 0)then return procname(n-1)+add(ithprime(j),j=1..n/2): fi: return procname(n-1)+ceil(n/2): end: seq(A160792(n),n=0..49); # _Nathaniel Johnston_, Jun 16 2011
%Y A160792 Cf. A000040, A160790, A160791, A160793.
%K A160792 easy,nonn
%O A160792 0,3
%A A160792 _Omar E. Pol_, May 29 2009
%E A160792 Terms after a(10) and edited by _Nathaniel Johnston_, Jun 16 2011