A305377 Tribonacci representation of primes, written in base 10.

2, 3, 5, 8, 12, 16, 20, 22, 27, 37, 40, 48, 52, 54, 67, 74, 82, 84, 91, 99, 101, 108, 130, 137, 147, 152, 154, 162, 164, 169, 194, 198, 205, 209, 256, 258, 265, 273, 277, 288, 294, 297, 309, 320, 324, 326, 341, 358, 363, 365, 387, 394, 396, 409, 419, 426, 434, 436, 515, 520, 522, 534, 554, 560

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10001

Maple

L[0]:= [0]: L[1]:= [1]:
for d from 2 to 15 do
  L[d]:= map(t -> (2*t, `if`(t mod 4 <> 3, 2*t+1, NULL)), L[d-1])
od:
A003726:=map(op, [seq(L[i], i=0..15)]):
seq(A003726[ithprime(i)+1], i=1..numtheory:-pi(nops(A003726)-1)); # Robert Israel, Jun 12 2018

Prog

(Python)
from sympy import prime
def A305377(n):
    m, tlist, s = prime(n), [1, 2, 4], 0
    while tlist[-1]+tlist[-2]+tlist[-3] <= m:
        tlist.append(tlist[-1]+tlist[-2]+tlist[-3])
    for d in tlist[::-1]:
        s *= 2
        if d <= m:
            s += 1
            m -= d
    return s # Chai Wah Wu, Jun 12 2018

Crossrefs

Equals A003726(prime(n)).

Cf. A278038, A305379.

Sequence in context: A028766 A342494 A022487 * A062489 A084624 A238548

Adjacent sequences: A305374 A305375 A305376 * A305378 A305379 A305380

Keyword

nonn,base

Author

N. J. A. Sloane, Jun 12 2018

Extensions

More terms from Robert Israel, Jun 12 2018

Status

approved