11311: Near Repdigit Palindrome 11..11311..11

First few terms (base 10): \[[1^*31^*_7]_n=\{3,71,2899,137943,6730403,\ldots\}\]

First few terms (base 7): \[\{\text{3},\text{131},\text{11311},\text{1113111},\text{111131111},\ldots\}\]

General Formula:\[[1^*31^*_7]_n={7\cdot7^{2n}+12\cdot7^{n}-1\over6}\]

Equivalent Patterns: \[[2^*62^*_7]_n=2\cdot[1^*31^*_7]_n\]

Table

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