A070330 Nontrivial numbers in which suffixing or inserting a 0 anywhere yields only composite numbers.

1, 7, 23, 29, 31, 43, 47, 73, 77, 83, 91, 101, 103, 107, 127, 143, 157, 173, 199, 209, 221, 233, 241, 247, 251, 257, 259, 271, 307, 313, 317, 343, 353, 359, 373, 377, 391, 409, 431, 433, 437, 439, 443, 461, 467, 469, 487, 497, 527, 541, 563, 569, 583, 589, 601

Offset

1,2

Comments

"Nontrivial" excludes multiples of 2, 3, or 5.

Links

Table of n, a(n) for n=1..55.

Crossrefs

Cf. A002808, A070331.

Cf. A008585, A005843, A017329.

Sequence in context: A031116 A044068 A109992 * A095314 A038948 A019389

Adjacent sequences: A070327 A070328 A070329 * A070331 A070332 A070333

Keyword

base,nonn

Author

Amarnath Murthy, May 11 2002

Extensions

More terms from Sascha Kurz, Feb 01 2003

a(1)=1 inserted by Sean A. Irvine, Jun 08 2024

Status

approved