Search a number
centered triangular n.  and  cyclic n.

First numbers that belong to both sets:

1, 19, 31, 85, 109, 199, 235, 409, 571, 631, 829, 901, 1135, 1219, 1489, 1585, 1891, 1999, 2341, 2461, 2839, 2971, 3385, 3529, 3979, 4135, 4621, 4789, 5311, 6049, 6835, 7039, 7669, 7885, 8551, 8779, 9481, 9721, 10459, 10711, 11485, 11749, 12559, 13681, 13969, 14851, 15151, 16069, 16381, 17335, 17659, 18649, 18985, 20011, 20359, 21421, 21781, 22879, 23251, 24385, 24769, 25939, 26335, 27541, 27949, 29191, 29611, 30889, 31321, 33079, 34429, 34885, 36271, 36739, 38161, 38641, 40099, 40591, 42085, 42589, 44119, 44635, 46201, 46729, 48331, 48871, 50509, 51061, 52735, 53299, 55009, 55585, 57331, 57919, 59701, 60301, 62119, 62731, 64585, 65209, 67099, 69661, 70309, 72271, 72931, 74929, 75601, 77635, 80389, 81085, 83191, 83899, 86041, 86761, 88939, 89671, 92629, 94879, 97921, 98689, 101011, 101791, 104149, 104941, 107335, 108139, 110569, 111385, 113851, 114679, 117181, 118021, 120559, 121411, 124849, 127459, 128335, 130981, 131869, 134551, 135451, 138169, 139081, 141835, 142759, 145549, 146485, 149311, 153121, 154081, 156979, 157951, 160885, 161869, 164839, 168841, 169849, 172891, 173911, 176989, 178021, 182179, 185329, 186385, 189571, 190639, 193861, 194941, 198199, 199291, 203689, 207019, 208135, 211501, 216031, 217171, 220609, 221761, 226399, 229909, 231085, 234631, 235819, 239401, 240601, 244219, 245431, 250309, 253999, 255235, 260209, 265231, 269029, 270301, 274135, 275419, 279289, 284491, 285799, 289741, 291061, 295039, 296371, 300385, 301729, 311221, 312589, 316711, 322249, 323641, 327835, 329239, 333469, 334885, 339151, 340579, 344881, 346321, 350659, 352111, 356485, 357949, 362359, 363835, 368281, 369769, 374251, 380269, 381781, 386335, 387859, 392449, 393985, 398611, 400159, 404821, 406381, 411079, 412651, 417385, 418969, 423739, 430141, 431749, 436591, 438211, 443089, 444721, 449635, 451279, 456229, 457885, 462871, 464539, 469561, 471241, 476299, 477991, 483085, 484789, 489919, 491635, 496801, 498529, 503731, 505471, 510709, 512461, 519499, 524809, 531931, 533719, 539101, 540901, 546319, 548131, 553585, 555409, 560899, 568261.

Some larger examples :