A163292 a(n) = n-th prime minus (number of digits of n-th prime written in base 4).

1, 2, 3, 5, 9, 11, 14, 16, 20, 26, 28, 34, 38, 40, 44, 50, 56, 58, 63, 67, 69, 75, 79, 85, 93, 97, 99, 103, 105, 109, 123, 127, 133, 135, 145, 147, 153, 159, 163, 169, 175, 177, 187, 189, 193, 195, 207, 219, 223, 225, 229, 235, 237, 247, 252, 258, 264, 266, 272, 276

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Formula

a(n) = A000040(n) - A163291(n).

Example

a(6) = 11 (= 13 - 2);
a(7) = 14 (= 17 - 3); ...
a(54) = 247 (= 251 - 4);
a(55) = 252 (= 257 - 5).

Maple

A000040 := proc(n) ithprime(n) ; end: A163291 := proc(n) max(1, ilog[4](A000040(n))+1) ; end: A163292 := proc(n) A000040(n)-A163291(n) ; end: seq(A163292(n), n=1..100) ; #R. J. Mathar, Jul 26 2009

Mathematica

#-IntegerLength[#, 4]&/@Prime[Range[60]] (* Harvey P. Dale, Dec 14 2015 *)

Prog

(PARI) a(n) = my(p=prime(n)); p - #digits(p, 4); \\ Michel Marcus, Mar 03 2019

Crossrefs

Cf. A000040, A004678, A163291, A163293 (analog in base 2).

Sequence in context: A161514 A215779 A140329 * A137518 A137509 A350916

Adjacent sequences: A163289 A163290 A163291 * A163293 A163294 A163295

Keyword

nonn,base

Author

Juri-Stepan Gerasimov, Jul 24 2009

Status

approved