A283610 Numbers n whose largest decimal digit is 7.

7, 17, 27, 37, 47, 57, 67, 70, 71, 72, 73, 74, 75, 76, 77, 107, 117, 127, 137, 147, 157, 167, 170, 171, 172, 173, 174, 175, 176, 177, 207, 217, 227, 237, 247, 257, 267, 270, 271, 272, 273, 274, 275, 276, 277, 307, 317, 327, 337, 347, 357, 367, 370, 371, 372

Offset

1,1

Comments

Numbers n such that A054055(n) = 7.

Number of terms less than 10^n is 8^n - 7^n.

Prime terms are in A106095.

Links

Muniru A Asiru, Table of n, a(n) for n = 1..5000

Mathematica

Select[Range[1000], Max[IntegerDigits[#]] == 7 &] (* Giovanni Resta, Mar 19 2017 *)

Prog

(Magma) [n: n in [1..100000] | Maximum(Setseq(Set(Sort(&cat[Intseq(n)])))) eq 7]
(PARI) for(n=1, 500, if(vecmax(digits(n))==7, print1(n, ", "))) \\ Indranil Ghosh, Mar 19 2017
(Python)
from sympy.ntheory.factor_ import digits
[n for n in range(1, 401) if max(digits(n)[1:]) == 7]  # Indranil Ghosh, Mar 19 2017
(GAP) Filtered([1..380], n->Maximum(ListOfDigits(n))=7); # Muniru A Asiru, Feb 27 2019

Crossrefs

Cf. A054055, A106095.

Cf. Sequences of numbers n whose largest decimal digit is k (for k = 1 - 9): A007088 (k = 1), A277964 (k = 2), A277965 (k = 3), A277966 (k = 4), A283608 (k = 5), A283609 (k = 6), this sequence (k = 7), A283611 (k = 8), A011539 (k = 9).

Sequence in context: A261934 A253075 A011537 * A043517 A277594 A160912

Adjacent sequences: A283607 A283608 A283609 * A283611 A283612 A283613

Keyword

nonn,base,easy

Author

Jaroslav Krizek, Mar 19 2017

Status

approved