A selection of a(n) values for sequence a036704

              n                       a(n)

              1:                         9
             10:                       349
            100:                    31,757
          1,000:                 3,144,725
         10,000:               314,190,877
        100,000:            31,416,240,789
      1,000,000:         3,141,595,797,869
     10,000,000:       314,159,296,779,497
    100,000,000:    31,415,926,850,054,729

    999,999,995: 3,141,592,625,315,439,093
    999,999,996: 3,141,592,631,598,698,993
    999,999,997: 3,141,592,637,881,878,521
    999,999,998: 3,141,592,644,165,098,369
    999,999,999: 3,141,592,650,448,223,941
  1,000,000,000: 3,141,592,656,731,409,109
  1,000,000,001: 3,141,592,663,014,609,245
  1,000,000,002: 3,141,592,669,297,774,161
  1,000,000,003: 3,141,592,675,581,006,833
  1,000,000,004: 3,141,592,681,864,162,401
  1,000,000,005: 3,141,592,688,147,345,113