A212647a(n) = product of exponents in canonical prime factorization of A181800(n) (n-th powerful number that is the first integer of its prime signature); a(1) = 1 by convention.
1, 2, 3, 4, 5, 4, 6, 6, 7, 8, 9, 8, 10, 12, 9, 12, …
The first 12 terms appear at position 447,446,626.
1415926535897932384626433…
…84460955058223172535940812848111745028410270193852…
…306744278622039194945047123713786960956364371917287…
…5522417189585361680594741234193398420218745649256443…
…51773117764897352309266612345888731028835156264460236…
…754934457066852943290726123454134362017705363653800762…
…7731747086228863598474351234546972612234791230105586971…
…32149603793029125680130812345466805430651879050841178938…
…662702862062349702192650123454667898947680954545197965700…
…6627028620623497021926501234546678989476809545451979657005…
…66270286206234970219265012345466789894768095454519796570050…
…662702862062349702192650123454667898947680954545197965700507…
| terms | string | first position | occurrences |
|---|---|---|---|
| 1 | 1 | 1 | 99,997,334 |
| 2 | 12 | 148 | 10,000,708 |
| 3 | 123 | 1,924 | 998,878 |
| 4 | 1234 | 13,807 | 100,085 |
| 5 | 12345 | 49,702 | 10,049 |
| 6 | 123454 | 1,528,033 | 996 |
| 7 | 1234546 | 10,545,033 | 104 |
| 8 | 12345466 | 14,841,765 | 10 |
| 9 | 123454667 | 447,446,626 | 2 |
| 10 | 1234546678 | 447,446,626 | 1 |
| 11 | 12345466789 | 447,446,626 | 1 |
| 12 | 123454667898 | 447,446,626 | 1 |
Searched the first 1,000,000,000 digits. Strings longer than 12 digits are not indexed.