A342259 Numbers k such that omega(k-1) = omega(k)-1 and omega(k+1) = omega(k)+1, where omega(m) is the number of distinct primes dividing m, A001221(m).

65, 104, 129, 164, 194, 272, 284, 314, 344, 384, 398, 464, 524, 608, 614, 626, 662, 692, 734, 758, 824, 968, 1025, 1094, 1172, 1238, 1280, 1304, 1364, 1424, 1448, 1454, 1532, 1544, 1595, 1658, 1664, 1682, 1724, 1754, 1832, 1868, 1869, 1934, 1952, 2000, 2001, 2012

Offset

1,1

Links

Hugo Pfoertner, Table of n, a(n) for n = 1..10000

Example

a(1)=65: 64=2^6 (1 distinct prime 2), 65=5*13 (2 distinct primes 5 and 13, 66=2*3*11 (3 distinct primes 2, 3, and 11).

Prog

(PARI) for(n=3, 2100, my(om=omega(n)); if(omega(n-1)==om-1&&omega(n+1)==om+1, print1(n, ", ")))

Crossrefs

Cf. A001221, A342258.

Sequence in context: A299456 A300094 A350241 * A075893 A064901 A039482

Adjacent sequences: A342256 A342257 A342258 * A342260 A342261 A342262

Keyword

nonn

Author

Hugo Pfoertner, Mar 07 2021

Status

approved