Least k such that base 5 representation of n begins at s(k), where s=A031251.

Terms

a(0) =3a(1) =2a(2) =1a(3) =6a(4) =3a(5) =31a(6) =22a(7) =12a(8) =25a(9) =23a(10) =2a(11) =19a(12) =10a(13) =15a(14) =13a(15) =11a(16) =1a(17) =7a(18) =5a(19) =36a(20) =26a(21) =16a(22) =6a(23) =46a(24) =33a(25) =253a(26) =178a(27) =3a(28) =255a(29) =32