Starting positions of strings of four 7's in the decimal expansion of Pi.

Terms

a(0) =1589a(1) =5241a(2) =5322a(3) =5863a(4) =29504a(5) =32478a(6) =33107a(7) =35457a(8) =40792a(9) =52313a(10) =69841a(11) =81356a(12) =87288a(13) =95735a(14) =96505a(15) =96984a(16) =126389a(17) =135083a(18) =137923a(19) =138108a(20) =145767a(21) =151494a(22) =156637a(23) =162248a(24) =162249a(25) =188346a(26) =197069a(27) =203946a(28) =208362a(29) =211588