A272141 Numbers such that the concatenation of their aliquot parts, in ascending order, are prime numbers.

9, 14, 21, 26, 27, 34, 35, 46, 49, 55, 57, 58, 62, 74, 98, 115, 118, 143, 155, 158, 161, 166, 169, 178, 183, 187, 194, 201, 202, 209, 214, 215, 218, 219, 221, 226, 245, 265, 279, 287, 295, 298, 309, 314, 323, 326, 327, 329, 335, 341, 355, 371, 374, 377, 381

Offset

1,1

Links

Paolo P. Lava, Table of n, a(n) for n = 1..10000

Example

Aliquot parts of 9 are 1, 3 and concat(1,3) = 13 is prime;
aliquot parts of 3127 are 1, 53, 59 and concat(1,53,59) = 15359 is prime.

Maple

with(numtheory): P:= proc(q) local a, b, k, n;
for n from 1 to q do a:=sort([op(divisors(n))]); b:=0;
for k from 1 to nops(a)-1 do b:=b*10^(ilog10(a[k])+1)+a[k]; od;
if isprime(b) then print(n); fi; od; end: P(10^9);

Mathematica

Select[Range@ 384, PrimeQ@ FromDigits@ Flatten@ IntegerDigits@ Most@ Divisors@ # &] (* Michael De Vlieger, Apr 21 2016 *)

Crossrefs

Cf. A176553, A272142.

Sequence in context: A272308 A186778 A070552 * A289548 A001198 A151915

Adjacent sequences: A272138 A272139 A272140 * A272142 A272143 A272144

Keyword

nonn,base,easy

Author

Paolo P. Lava, Apr 21 2016

Status

approved