A340916 Integers m that have at least one divisor d such that d+m/d is a substring of m.

4, 272, 352, 400, 414, 418, 425, 432, 448, 450, 465, 490, 504, 518, 572, 585, 598, 720, 732, 744, 756, 768, 972, 1092, 1104, 1152, 1210, 1221, 1232, 1243, 1254, 1265, 1276, 1287, 1298, 1309, 1792, 1872, 1887, 1890, 1904, 1914, 1920, 1950, 1972, 2100, 2112, 2672

Offset

1,1

Comments

These are the resulting product strings in A339144.

Links

Table of n, a(n) for n=1..48.

Example

272 = 4*68 contains 4+68 = 72 as a substring, so 272 is a term.

Mathematica

q[n_] := AnyTrue[Divisors[n], SequenceCount[IntegerDigits[n], IntegerDigits[# + n/#]] > 0 &]; Select[Range[3000], q] (* Amiram Eldar, Jan 26 2021 *)

Prog

(PARI) isok(n) = {fordiv(n, d, if (#strsplit(Str(n), Str(d+n/d)) > 1, return(1)); if (d^2 > n, return(0)); ); }

Crossrefs

Cf. A339144, A340917.

Sequence in context: A357559 A108134 A221081 * A000320 A101758 A134786

Adjacent sequences: A340913 A340914 A340915 * A340917 A340918 A340919

Keyword

nonn,base

Author

Michel Marcus, Jan 26 2021

Status

approved