A300737 Numbers of the form (k*i + 1)*(k*j - 1) with i, j >= 1 and k >= 2.

3, 5, 7, 8, 9, 11, 13, 14, 15, 17, 19, 20, 21, 23, 24, 25, 26, 27, 29, 31, 32, 33, 35, 37, 38, 39, 41, 43, 44, 45, 47, 48, 49, 50, 51, 53, 54, 55, 56, 57, 59, 61, 62, 63, 64, 65, 67, 68, 69, 71, 73, 74, 75, 77, 79, 80, 81, 83, 84, 85, 86, 87, 89, 90, 91, 92, 93, 95, 97, 98, 99, 101

Offset: 1

Author

Gionata Neri, Mar 11 2018

Keywords

• nonn

Crossrefs

Cf. A056868.

Programs

PARI

limit=100; v=vector(limit); for(n=0,limit, for(k=2,floor(limit^(1/2)), for(i=1,limit/k, for(j=1,limit/k,if(n==(k*i+1)*(k*j-1),v[n]=1,))))); for(n=1,limit,if(v[n],print1(n", ")))