A108322 "Binary prime squares": a(n) = n^2 written in base 2 and interpreted as a base-10 number, if that number is prime; a(n) = 0 otherwise.

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1101001001, 0, 0, 0, 0, 0, 0, 0, 0, 0, 10111110001, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 101000101001, 0, 101011111001, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1000110001001, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset

1,29

Comments

Another definition: numbers having only digits 1 and 0, which, read in base 10 are primes and in base 2 are perfect squares.

Links

Table of n, a(n) for n=1..76.

Example

a(5)=0 because 5^2 = 25 = 11001_2, and the decimal number 11001 is not prime.
a(29)=1101001001 because 29^2 = 841 = 1101001001_2, and the decimal number 1101001001 is prime.

Crossrefs

Cf. A108323, A108324, A108325.

Sequence in context: A134595 A217610 A219319 * A108323 A154474 A096553

Adjacent sequences: A108319 A108320 A108321 * A108323 A108324 A108325

Keyword

easy,nonn,base

Author

Alexandre Wajnberg, Jun 30 2005

Extensions

Edited by Jon E. Schoenfield, Sep 23 2018

Offset corrected by Michel Marcus, Sep 24 2018

Status

approved