A319406 Write n-th prime in binary, then increase each run of 0's by one 0, and increase each run of 1's by one 1. a(n) is the decimal equivalent of the result.

12, 7, 51, 15, 103, 115, 195, 199, 207, 243, 63, 1587, 1635, 1639, 415, 1843, 487, 499, 775, 783, 3171, 799, 3271, 3299, 899, 3635, 911, 3687, 3699, 963, 255, 1543, 6243, 6247, 25395, 6351, 6387, 6535, 6543, 26227, 6599, 26419, 1663, 1795, 7219, 1807, 7367

Offset

1,1

Comments

Apply A175046 to the primes.

Links

Rémy Sigrist, Table of n, a(n) for n = 1..10000

Prog

(Python)
from sympy import prime
def a(n):
    b = bin(prime(n))[2:]
    return int(b.replace("01", "001").replace("10", "110") + b[-1], 2)
print([a(n) for n in range(1, 48)]) # Michael S. Branicky, Dec 07 2021

Crossrefs

Cf. A175046.

A companion to A318923.

Sequence in context: A364135 A305939 A206423 * A038333 A185259 A090438

Adjacent sequences: A319403 A319404 A319405 * A319407 A319408 A319409

Keyword

nonn,base

Author

N. J. A. Sloane, Sep 19 2018

Extensions

More terms from Rémy Sigrist, Sep 20 2018

Status

approved