22221: Near Repdigit 22..221

First few terms (base 10): \[[2^*1_5]_n=\{1,11,61,311,1561,\ldots\}\]

First few terms (base 5): \[\{\text{1},\text{21},\text{221},\text{2221},\text{22221},\ldots\}\]

General Formula:\[[2^*1_5]_n={5\cdot5^{n}-3\over2}\]

Equivalent Patterns: \[[4^*2_5]_n=2\cdot[2^*1_5]_n\]

Table

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