A077684 Squarefree numbers with 8 as their initial (leftmost) digit.

82, 83, 85, 86, 87, 89, 802, 803, 805, 806, 807, 809, 811, 813, 814, 815, 817, 818, 821, 822, 823, 826, 827, 829, 830, 831, 834, 835, 838, 839, 842, 843, 849, 851, 853, 854, 857, 858, 859, 861, 862, 863, 865, 866, 869, 870, 871, 874, 877, 878, 879, 881, 883

Offset

1,1

Comments

Intersection of A005117 and A217401. - Michel Marcus, Sep 14 2013

Lower density is 3/(40*Pi^2), upper density is 20/(27*Pi^2). - Charles R Greathouse IV, Nov 05 2017

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

Select[Range[900], SquareFreeQ[#]&&First[IntegerDigits[#]]==8&]  (* Harvey P. Dale, Feb 22 2011 *)

Prog

(PARI) is(n)=n>81 && digits(n)[1]==8 && issquarefree(n) \\ Charles R Greathouse IV, Nov 05 2017

Crossrefs

Cf. A077677, A077678, A077679, A077680, A077681, A077682, A077683, A077685.

Sequence in context: A080536 A043632 A296880 * A044982 A181468 A081648

Adjacent sequences: A077681 A077682 A077683 * A077685 A077686 A077687

Keyword

base,easy,nonn

Author

Amarnath Murthy, Nov 16 2002

Extensions

More terms from Sascha Kurz, Jan 28 2003

Definition clarified by Harvey P. Dale, Feb 22 2011

Status

approved