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decagonal n.  and  unprimeable n.

First numbers that belong to both sets:

3052, 5365, 6930, 7612, 9072, 13282, 17226, 17755, 18292, 23485, 26650, 27972, 32130, 35815, 37345, 38122, 41310, 45475, 59170, 61132, 64135, 65152, 69300, 74665, 82512, 89550, 94402, 96876, 99382, 117820, 121975, 126202, 146880, 175770, 187705, 189442, 218322, 220195, 225862, 233530, 237412, 239365, 243295, 253260, 257302, 299482, 312760, 324045, 347215, 351945, 368752, 371185, 376075, 383470, 388440, 393442, 401005, 421525, 429352, 450576, 466830, 475065, 480595, 517320, 528892, 531805, 534726, 537655, 546490, 552420, 558382, 597915, 601012, 607230, 613480, 622915, 626076, 632422, 645210, 651652, 671170, 677740, 687655, 690976, 694305, 704340, 711070, 717832, 728035, 731452, 752122, 759076, 780130, 790765, 801472, 823102, 826735, 830376, 837682, 897282, 908685, 912502, 935572, 947215, 951112, 974662, 998500, 1038870, 1055242, 1059355, 1067605, 1096732, 1105126, 1109335, 1122010, 1139022, 1156162, 1164780, 1182112, 1186465, 1208350, 1217160, 1226002, 1270692, 1284255, 1297890, 1307020, 1316182, 1325376, 1329985, 1353150, 1409562, 1428622, 1462285, 1471975, 1476832, 1496340, 1506142, 1525842, 1545670, 1560625, 1565626, 1585710, 1605922, 1636480, 1688050, 1719376, 1729882, 1761592, 1782892, 1836702, 1874845, 1902330, 1930015, 1935576, 1941145, 1997275, 2071440, 2094532, 2100325, 2106126, 2117752, 2141100, 2152822, 2170465, 2176362, 2247750, 2271802, 2283876, 2332492, 2350855, 2400175, 2412585, 2418802, 2431260, 2456272, 2481412, 2544822, 2589685, 2609032, 2621970, 2654455, 2660976, 2700270, 2713432, 2720025, 2726626, 2766400, 2786395, 2799765, 2819880, 2853565, 2901060, 2914702, 2935225, 2990305, 3052882, 3066876, 3080902, 3094960, 3109050, 3137326, 3151512, 3194262, 3201415, 3237300, 3251710, 3266152, 3273385, 3287875, 3295132, 3368142, 3419725, 3434535, 3456810, 3501576, 3516562, 3531580, 3561712, 3584395, 3622360, 3645235, 3668182, 3698890, 3714292, 3737455, 3776220, 3815185, 3854350, 3901612, 3917430, 3933280, 3949162, 3957115, 3965076, 3973045, 3981022, 4013010, 4029052, 4109742, 4117855, 4142242, 4199425, 4224052, 4257000, 4298365, 4356612, 4364965, 4406850, 4465825, 4474282, 4491220, 4525192, 4542226, 4550755, 4576390, 4619275, 4636485, 4645102, 4662360, 4705645, 4714326, 4723015, 4766580, 4784062, 4854310, 4889626, 4942840, 4960642, 4969555, 5032170, 5050132, 5059125, 5068126, 5077135, 5104210, 5140422, 5149495, 5158576, 5194980.

Some larger examples :