a(n) is root of square starting with digit 5: first term of runs.

Terms

a(0) =23a(1) =71a(2) =224a(3) =708a(4) =2237a(5) =7072a(6) =22361a(7) =70711a(8) =223607a(9) =707107a(10) =2236068a(11) =7071068a(12) =22360680a(13) =70710679a(14) =223606798a(15) =707106782a(16) =2236067978a(17) =7071067812a(18) =22360679775a(19) =70710678119a(20) =223606797750a(21) =707106781187