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A243619 Prime numbers n whose digital sum equals the number of bits in its binary expansion. 3
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 (list; graph; refs; listen; history; text; internal format)
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 A284516

Adjacent sequences:  A243616 A243617 A243618 * A243620 A243621 A243622

KEYWORD

nonn,base

AUTHOR

Andreas Boe, Jun 07 2014

STATUS

approved

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Last modified June 20 23:24 EDT 2021. Contains 345312 sequences. (Running on oeis4.)