This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A346651 #33 Aug 21 2021 15:46:46 %S A346651 1,2,2,2,3,2,2,3,2,2,3,3,2,4,2,2,3,2,3,4,2,2,3,2,3,5,2,3,3,2,2,4,3,2, %T A346651 3,4,2,4,2,3,3,2,2,5,3,2,6,2,2,4,2,3,3,3,2,4,2,4,3,3,3,5,2,2,3,2,2,7, %U A346651 4,2,4,2,2,4,3,3,3,2,3,6,2,3,3,4,2,4,2,2,5,2 %N A346651 a(n) is the number of divisors of A139245(n) ending with 2. %C A346651 a(n) is odd if and only if A139245(n) either is the square of a number ending with 2 or has a unitary prime divisor ending with 7. %C A346651 The term 1 appears only for n = 1 in corresponding to A139245(1) = 4. %e A346651 a(14) = 4 since there are 4 divisors of A139245(14) = 264 ending with 2: 2, 12, 22 and 132. %t A346651 a[n_]:=Length[Drop[Select[Divisors[20n-16], (Last[IntegerDigits[#]]==2&)]]]; Array[a, 90] %o A346651 (PARI) a(n) = sumdiv(20*n-16, d, (d%10) == 2); \\ _Michel Marcus_, Jul 26 2021 %Y A346651 Cf. A000005, A017293 (numbers ending with 2), A017294 (squares of numbers ending with 2), A030432, A056169, A139245 (product of two numbers ending with 2), A346388, A346389. %K A346651 nonn,base %O A346651 1,2 %A A346651 _Stefano Spezia_, Jul 26 2021