A030756 n-th number k such that s(k)=4, where s=A030747.

1, 11, 28, 38, 60, 88, 91, 107, 109, 131, 153, 206, 267, 302, 379, 429, 477, 518, 522, 527, 570, 572, 580, 633, 637, 692, 747, 755, 760, 826, 889, 892