A134623 a(n) = the n-th positive integer which is missing from A134624.

2, 3, 5, 7, 8, 9, 11, 12, 13, 15, 17, 19, 20, 21, 23, 25, 28, 29, 30, 31, 32, 33, 35, 36, 37, 39, 41, 43, 44, 45, 47, 48, 49, 51, 53, 54, 55, 56, 57, 59, 61, 63, 65, 67, 68, 69, 71, 73, 76, 77, 78, 79, 80, 81, 83, 84, 85, 87, 89, 91, 92, 93, 95, 97, 100, 101, 102

Offset: 1

Author

Leroy Quet, Nov 04 2007

Keywords

• nonn

Comments

A134624(1) = 1. A134624(n) is the smallest integer which is > A134624(n-1) and is different from and not coprime to a(n-1). [corrected by Michel Marcus, Sep 06 2019]

Crossrefs

Cf. A053661, A134624.

Programs

PARI

missing(n, v) = {my(nb = 0, k = 1, s = Set(v), ok = 0); while(!ok, if (! setsearch(s, k), nb++); ok = (nb == n); if (!ok, k++);); k;}
nextt(start, cop) = {my(k = max(start+1, cop+1)); while(gcd(k, cop) == 1, k++); k;}
list3(nn) = {my(v3 = vector(nn), v4 = vector(nn)); v4[1] = 1; for (n=1, nn, v3[n] = missing(n, v4); if (n+1 > nn, break); v4[n+1] = nextt(v4[n], v3[n]);); v3} \\ Michel Marcus, Sep 06 2019

Extensions

More terms from Michel Marcus, Sep 06 2019