A077719 Primes which can be expressed as sum of distinct powers of 5.

5, 31, 131, 151, 631, 751, 3251, 3881, 16381, 19381, 19501, 19531, 78781, 78901, 81281, 81401, 81901, 82031, 93901, 94531, 97001, 97501, 97651, 390751, 390781, 393901, 394501, 406381, 468781, 469501, 471901, 472631, 484531, 485131, 487651, 1953151, 1953901

Offset

1,1

Comments

Primes whose base 5 representation contains only zeros and 1's.

Links

Michael S. Branicky, Table of n, a(n) for n = 1..10000

Prog

(Python)
from sympy import isprime
def aupton(terms):
  k, alst = 0, []
  while len(alst) < terms:
    k += 1
    t = sum(5**i*int(di) for i, di in enumerate((bin(k)[2:])[::-1]))
    if isprime(t): alst.append(t)
  return alst
print(aupton(37)) # Michael S. Branicky, May 31 2021

Crossrefs

Cf. A020449, A000695, A033042, A077717, A077718, A077720, A077721, A077722.

Sequence in context: A267938 A041303 A184446 * A235462 A005826 A293716

Adjacent sequences: A077716 A077717 A077718 * A077720 A077721 A077722

Keyword

nonn

Author

Amarnath Murthy, Nov 19 2002

Extensions

More terms from Sascha Kurz, Jan 03 2003

a(36) and beyond from Michael S. Branicky, May 31 2021

Status

approved