11511: Near Repdigit Palindrome 11..11511..11

First few terms (base 10): \[[1^*51^*_9]_n=\{5,127,7705,600787,48453805,\ldots\}\]

First few terms (base 9): \[\{\text{5},\text{151},\text{11511},\text{1115111},\text{111151111},\ldots\}\]

General Formula:\[[1^*51^*_9]_n={9\cdot9^{2n}+32\cdot9^{n}-1\over8}\]

Equivalent Patterns: (none)

Table

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