A090853 a(n) is the least positive integer such that the arithmetic-geometric mean satisfies: floor( agm(a(n),a(n-2)) ) = a(n-1) for n>2, with a(1)=1, a(2)=2.
1, 2, 4, 7, 12, 19, 28, 40, 55, 73, 94, 118, 145, 176, 211, 250, 293, 340, 391, 446, 505, 568, 635, 706, 781, 860, 943, 1030, 1121, 1216, 1315, 1418, 1525, 1637, 1754, 1876, 2003, 2135, 2272, 2414, 2561, 2713, 2870, 3032, 3199, 3371, 3548, 3730, 3917, 4109
Offset: 1