A364435 The first term in a run of at least 4 consecutive numbers each with exactly 5 distinct prime factors (i.e. belong to A051270).

21871365, 37055184, 37227993, 39272583, 41205603, 43067463, 44012682, 44126949, 47761635, 48806274, 49362234, 49613484, 50582103, 52953795, 54244068, 60529077, 60988653, 61042069, 62319465, 63850344, 66068793, 66709683, 66710004, 67874079, 67974312, 68294148, 68529900

Offset

1,1

Links

Table of n, a(n) for n=1..27.

Example

21871365 is in the sequence as it starts a run of at least 4 consecutive numbers each with exactly 5 distinct prime factors.
That is each of 21871365 = 3 * 5 * 29 * 137 * 367, 21871365 + 1 = 21871366 = 2 * 11 * 37 * 97 * 277, 21871365 + 2 = 21871367 = 7*17*23*61*131, 21871365 + 3 = 21871368 = 2^3 * 3^2 * 31 * 41 * 239 have 5 distinct prime factors.

Prog

(PARI) upto(n) = {my(res = List(), streak = 0); n+=3; forfactored(i = 1, n, if(omega(i[2]) == 5, streak++; if(streak >= 4, listput(res, i[1]-3)), streak = 0)); res}

Crossrefs

Cf. A051270, A364266.

Sequence in context: A250912 A251998 A210389 * A118860 A186595 A210076

Adjacent sequences: A364432 A364433 A364434 * A364436 A364437 A364438

Keyword

nonn

Author

David A. Corneth, Jul 24 2023

Status

approved