A393436 - OEIS

%I #12 Mar 10 2026 13:38:22

%S 1,3,7,13,23,31,43,59,73,97,127,149,167,193,227,263,283,311,349,389,

%T 421,463,509,557,601,653,709,769,823,881,947,997,1061,1123,1193,1277,

%U 1367,1439,1517,1597,1693,1787,1861,1949,2017,2099,2203,2279,2371,2473,2579,2677,2777,2887,2999,3119,3251,3359,3481,3607,3761,3847,3989,4127

%N Partial sums of A390314.

%H Michael De Vlieger, <a href="/A393436/b393436.txt">Table of n, a(n) for n = 1..10000</a>

%t Block[{c, k, s, p, u, nn}, nn = 65; c[_] := False; k = s = p = 1; c[1] = True; u = 2; Reap[Do[k = u; While[Or[c[k], ! CoprimeQ[s + k, p*k]], k++]; c[k] = True; Sow[s]; s += k; p *= k; If[k == u, While[c[u], u++]], {n, 2, nn}] ][[-1, 1]] ] (* _Michael De Vlieger_, Mar 10 2026 *)

%Y Cf. A390314, A393436.

%Y Similar to, but different from, A291544, A291546.

%K nonn

%O 1,2

%A _N. J. A. Sloane_, Mar 10 2026