A326740 Numbers which converge to 7 under repeated application of the powertrain map of A133500.

7, 71, 75, 107, 117, 127, 137, 147, 157, 167, 177, 187, 197, 207, 307, 407, 507, 523, 543, 607, 707, 711, 723, 747, 751, 807, 907, 1071, 1075, 1171, 1175, 1271, 1275, 1371, 1375, 1471, 1475, 1571, 1575, 1671, 1675, 1771, 1775, 1871, 1875, 1971, 1975, 2071

Offset: 1

Author

Martin Renner, Jul 22 2019

Keywords

• nonn
• base
• easy

Examples

			75 -> 7^5 = 16807 -> 1^6*8^0*7 = 7.
		

Crossrefs

Cf. A133500, A133501, A135384, A135385, A309385, A326733, A326734, A326735, A326736, A326737, A326738, A326739, A326741, A326742.