A262428 Concatenate the n-th prime with the n-th semiprime.

24, 36, 59, 710, 1114, 1315, 1721, 1922, 2325, 2926, 3133, 3734, 4135, 4338, 4739, 5346, 5949, 6151, 6755, 7157, 7358, 7962, 8365, 8969, 9774, 10177, 10382, 10785, 10986, 11387, 12791, 13193, 13794, 13995, 149106, 151111, 157115, 163118, 167119, 173121, 179122, 181123, 191129, 193133, 197134

Offset

1,1

Comments

Sequence is simply visual coexistence of two core and nice sequences. - Altug Alkan, Sep 28 2015

Links

Table of n, a(n) for n=1..45.

Mathematica

t = Select[Range@ 10000, PrimeOmega@ # == 2 &]; Table[FromDigits@ Join[IntegerDigits@ Prime@ n, IntegerDigits@ t[[n]]], {n, 50}] (* Michael De Vlieger, Sep 22 2015 *)

Prog

(PARI) m=0; for (n=1, 250, if (bigomega(n) == 2, m++; print1(Str(prime(m), n), ", "))) \\ Altug Alkan, Sep 23 2015
(Perl) use ntheory ":all"; my $i=0; forprimes { print ++$i, " $_", nth_semiprime($i), "\n"; } 100; # Dana Jacobsen, Oct 11 2018

Crossrefs

Cf. A000040, A001358, A001097, A065870.

Sequence in context: A003138 A003177 A038530 * A281925 A261022 A179152

Adjacent sequences: A262425 A262426 A262427 * A262429 A262430 A262431

Keyword

nonn,base,easy

Author

Giovanni Teofilatto, Sep 22 2015

Status

approved