A241576 Third differences of A001521.

0, 1, 0, 0, 1, 0, 1, 2, 2, 2, 4, 6, 8, 10, 16, 22, 31, 44, 62, 88, 124, 176, 248, 352, 497, 702, 994, 1406, 1987, 2812, 3975, 5622, 7951, 11244, 15902, 22488, 31804, 44976, 63607, 89954, 127213, 179908, 254427, 359814, 508855, 719628, 1017709

Offset: 1

Author

N. J. A. Sloane, Apr 27 2014

Keywords

• nonn

Crossrefs

Cf. A001521, A017911, A190660.

Programs

Mathematica

Differences[NestList[Floor[Sqrt[2#(#+1)]]&,1,50],3] (* Harvey P. Dale, Dec 17 2019 *)