cp's OEIS Frontend

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.

A322901 Numbers whose prime indices are all powers of the same number.

This page as a plain text file.
%I A322901 #7 Dec 31 2018 13:18:17
%S A322901 1,2,3,4,5,6,7,8,9,10,11,12,13,14,16,17,18,19,20,21,22,23,24,25,26,27,
%T A322901 28,29,31,32,34,36,37,38,40,41,42,43,44,46,47,48,49,50,52,53,54,56,57,
%U A322901 58,59,61,62,63,64,67,68,71,72,73,74,76,79,80,81,82,83
%N A322901 Numbers whose prime indices are all powers of the same number.
%C A322901 A prime index of n is a number m such that prime(m) divides n.
%e A322901 The Heinz number of an integer partition (y_1, ..., y_k) is prime(y_1) * ... * prime(y_k). The sequence of all integer partitions whose Heinz numbers belong to the sequence begins: (), (1), (2), (11), (3), (21), (4), (111), (22), (31), (5), (211), (6), (41), (1111), (7), (221), (8), (311), (42), (51), (9), (2111), (33), (61), (222), (411).
%t A322901 primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
%t A322901 radbase[n_]:=n^(1/GCD@@FactorInteger[n][[All,2]]);
%t A322901 Select[Range[100],SameQ@@radbase/@DeleteCases[primeMS[#],1]&]
%Y A322901 Cf. A001597, A018819, A052409, A052410, A056239, A072720, A072721,  A302242, A302593, A322900, A322902, A322903.
%K A322901 nonn
%O A322901 1,2
%A A322901 _Gus Wiseman_, Dec 30 2018