A243619 Prime numbers n whose digital sum equals the number of bits in its binary expansion.

2, 13, 23, 233, 251, 523, 541, 613, 631, 811, 1009, 1091, 1109, 1163, 1181, 1217, 1307, 1361, 1433, 1451, 1523, 1613, 1721, 1811, 1901, 2027, 4153, 4243, 4261, 4423, 4441, 4513, 4603, 4621, 4801, 5107, 5233, 5323, 5413, 5431

Offset

1,1

Comments

Subset of A243615.

Links

Andreas Boe, Table of n, a(n) for n = 1..10000

Example

23 -> 2+3=5,  23=10111 -> Five bits.

Mathematica

Select[Prime[Range[800]], Total[IntegerDigits[#]]==IntegerLength[#, 2]&] (* Harvey P. Dale, Nov 05 2019 *)

Prog

(PARI) isok(n) = isprime(n) && (sumdigits(n) == #binary(n)); \\ Michel Marcus, Jun 08 2014

Crossrefs

Cf. A243615 (same principle but covers all natural numbers).

Sequence in context: A079397 A118524 A029971 * A243620 A090526 A362433

Adjacent sequences: A243616 A243617 A243618 * A243620 A243621 A243622

Keyword

nonn,base

Author

Andreas Boe, Jun 07 2014

Status

approved