21111: Near Repdigit 211..11

First few terms (base 10): \[[21^*_4]_n=\{2,9,37,149,597,\ldots\}\]

First few terms (base 4): \[\{\text{2},\text{21},\text{211},\text{2111},\text{21111},\ldots\}\]

General Formula:\[[21^*_4]_n={7\cdot4^{n}-1\over3}\]

Equivalent Patterns: (none)

Table

No table data.