A364586 a(n) is the least number with exactly n divisors of the form 5*k+1.

1, 6, 36, 66, 252, 336, 672, 1008, 3528, 2016, 4032, 3696, 9072, 7392, 13104, 11088, 36288, 38304, 26208, 22176, 68544, 44352, 91728, 66528, 154224, 99792, 209664, 96096, 301392, 144144, 222768, 188496, 487872, 399168, 471744, 421344, 1079568, 288288, 1097712, 432432

Offset: 1

Author

Ilya Gutkovskiy, Jul 28 2023

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..100

Crossrefs

Cf. A001876, A005179, A038547, A364598, A364599, A364600.

Programs

PARI

a(n) = my(k=1); while (sumdiv(k, d, (d%5)==1) != n, k++); k; \\ Michel Marcus, Jul 29 2023

PARI

list(nmax) = {my(v = vector(nmax), c = 0, k = 1, i); while(c < nmax, i = sumdiv(k, d, d % 5 == 1); if(i <= nmax && v[i] == 0, c++; v[i] = k); k++); v;} \\ Amiram Eldar, Jan 28 2025