612350domain: NAppears in sequencesNumber of happy numbers without zeros and with digits in nondecreasing order <= 10^n.at n=18A219667Number of nX3 0..1 arrays with every element unequal to 0, 1, 3, 4 or 5 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=14A326160