A214755 Primes formed by concatenating odd primes.

37, 53, 73, 113, 137, 173, 193, 197, 233, 293, 311, 313, 317, 331, 337, 347, 353, 359, 367, 373, 379, 383, 389, 397, 433, 523, 541, 547, 557, 571, 577, 593, 613, 617, 673, 677, 719, 733, 743, 757, 761, 773, 797, 977, 1013, 1033, 1093, 1097, 1117, 1123, 1129, 1153

Offset

1,1

Comments

Subsequence of A019549.

Links

David Radcliffe, Table of n, a(n) for n = 1..10000

Prog

(Python)
from sympy import primerange
oddPrimes = list(primerange(3, 1154))
def tryPartitioning(binString):  # First digit is not 0
    l = len(binString)
    for t in range(1, l):
        substr1 = binString[:t]
        if (int(substr1) in oddPrimes) or (t>=2 and tryPartitioning(substr1)):
            substr2 = binString[t:]
            if substr2[0]!='0':
                if (int(substr2) in oddPrimes) or (l-t>=2 and tryPartitioning(substr2)):
                    return 1
    return 0
for p in oddPrimes:
    if tryPartitioning(str(p)):
        print(p, end=', ')

Crossrefs

Cf. A019549, A214754.

Sequence in context: A060330 A302720 A304358 * A101940 A330339 A036540

Adjacent sequences: A214752 A214753 A214754 * A214756 A214757 A214758

Keyword

nonn,base

Author

Alex Ratushnyak, Aug 03 2012

Status

approved