A217397 Numbers starting with 4.

4, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 400, 401, 402, 403, 404, 405, 406, 407, 408, 409, 410, 411, 412, 413, 414, 415, 416, 417, 418, 419, 420, 421, 422, 423, 424, 425, 426, 427, 428, 429, 430, 431, 432, 433, 434, 435, 436, 437, 438, 439, 440, 441, 442

Offset

1,1

Comments

The lower and upper asymptotic densities of this sequence are 1/36 and 2/9, respectively. - Amiram Eldar, Feb 27 2021

Links

Jeremy Gardiner, Table of n, a(n) for n = 1..1111

Index entries for 10-automatic sequences.

Formula

a(n) = n + (35*10^floor(log_10(9*n-8))-8)/9. - Alan Michael Gómez Calderón, May 17 2023

Mathematica

Select[Range[1000], IntegerDigits[#][[1]] == 4 &] (* T. D. Noe, Oct 02 2012 *)

Crossrefs

Cf. A000867, A011534.

Subsequences include: A045710, A077329, A077680, A106414, A106424.

Cf. A131835, A217394, A217395, A217398, A217399, A217400, A217401, A217402.

Sequence in context: A080271 A275361 A274686 * A104292 A077329 A169967

Adjacent sequences: A217394 A217395 A217396 * A217398 A217399 A217400

Keyword

nonn,base,easy

Author

Jeremy Gardiner, Oct 02 2012

Status

approved