A320865 Powers of 2 with initial digit 9.

9007199254740992, 9223372036854775808, 9444732965739290427392, 9671406556917033397649408, 9903520314283042199192993792, 91343852333181432387730302044767688728495783936, 93536104789177786765035829293842113257979682750464

Offset: 1

Author

Muniru A Asiru, Nov 21 2018

Keywords

• base
• nonn

Links

• Muniru A Asiru, Table of n, a(n) for n = 1..150
• Index to divisibility sequences

Crossrefs

Cf. A000079 (powers of 2), A008952 (leading digit of 2^n), A217402 (numbers starting with 9).

Powers of 2 with initial digit k, (k = 1..9): A067488, A067480, A320859, A320860, A320861, A320862, A320863, A320864, this sequence.

Programs

GAP

Filtered(List([0..200],n->2^n),i->ListOfDigits(i)[1]=9);

Maple

select(x->"9"=""||x[1],[2^n$n=0..200])[];

Mathematica

Select[2^Range[200], IntegerDigits[#][[1]] == 9 &] (* Amiram Eldar, Nov 21 2018 *)

PARI

select(x->(digits(x)[1]==9), vector(200, n, 2^n)) \\ Michel Marcus, Nov 21 2018