login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A214755 Primes formed by concatenating odd primes. 0
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Subsequence of A019549.

LINKS

Table of n, a(n) for n=1..52.

PROG

(Python)

# oddPrimes = [3, ..., 1153]

def tryPartioning(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 tryPartioning(substr1)):

            substr2 = binString[t:]

            if substr2[0]!='0':

                if (int(substr2) in oddPrimes) or (l-t>=2 and tryPartioning(substr2)):

                    return 1

    return 0

for p in oddPrimes:

    if tryPartioning(str(p)):

        print p,

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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 1 22:12 EST 2021. Contains 349435 sequences. (Running on oeis4.)