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A320860
Powers of 2 with initial digit 4.
7
4, 4096, 4194304, 4294967296, 4398046511104, 4503599627370496, 4611686018427387904, 4722366482869645213696, 4835703278458516698824704, 4951760157141521099596496896, 40564819207303340847894502572032, 41538374868278621028243970633760768
OFFSET
1,1
COMMENTS
Differs from A067482 first at n = 11.
MAPLE
select(x->"4"=""||x[1], [2^n$n=0..150])[];
MATHEMATICA
Select[2^Range[160], First[IntegerDigits[#]] == 4 &] (* G. C. Greubel, Oct 27 2018 *)
PROG
(GAP) Filtered(List([0..150], n->2^n), i->ListOfDigits(i)[1]=4);
(PARI) select(x->(digits(x)[1]==4), vector(200, n, 2^n)) \\ Michel Marcus, Oct 26 2018
(Magma) [2^n: n in [1..160] | Intseq(2^n)[#Intseq(2^n)] eq 4]; // G. C. Greubel, Oct 27 2018
CROSSREFS
Cf. A000079 (Powers of 2), A008952 (leading digit of 2^n), A217397 (numbers starting with 4).
Powers of 2 with initial digit k, (k = 1..4): A067488, A067480, A320859, this sequence.
Sequence in context: A110104 A024061 A013830 * A067482 A249804 A079682
KEYWORD
base,nonn
AUTHOR
Muniru A Asiru, Oct 22 2018
STATUS
approved