Question 894440
My definition p(n)=p(n-1)+1

11+15+19..+(4n+7)+(4(n+1)+7)=2(n+1)^2+9(n+1)
 =2(n^2+2n+1)+9n+1
 = 2n^2+9n + 4n+2+9
  =2n^2+9n + 4n+11
Therefore works for the step up case 
= 4(n+1)+7=4n+11