Numbers k such that phi(k, 2) = phi(k+1, 2), where phi(k, 2) = A002472(k).

Terms

a(0) =1a(1) =2a(2) =9a(3) =34a(4) =50a(5) =153a(6) =274a(7) =321a(8) =2841a(9) =4610a(10) =7474a(11) =8254a(12) =10250a(13) =13430a(14) =22149a(15) =38961a(16) =51981a(17) =86845a(18) =91310a(19) =198057a(20) =237325a(21) =367629a(22) =374541a(23) =394834a(24) =419169a(25) =489445a(26) =513890a(27) =516350a(28) =519230a(29) =570230