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.

A325796 Numbers with at least as many divisors as the sum of their prime indices.

This page as a plain text file.
%I A325796 #5 May 23 2019 14:51:35
%S A325796 1,2,3,4,6,8,10,12,16,18,20,24,28,30,32,36,40,42,48,54,56,60,64,66,70,
%T A325796 72,80,84,88,90,96,100,108,112,120,126,128,132,140,144,150,156,160,
%U A325796 162,168,176,180,192,198,200,204,208,210,216,220,224,228,234,240
%N A325796 Numbers with at least as many divisors as the sum of their prime indices.
%C A325796 A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798, with sum A056239(n).
%e A325796 The sequence of terms together with their prime indices begins:
%e A325796     1: {}
%e A325796     2: {1}
%e A325796     3: {2}
%e A325796     4: {1,1}
%e A325796     6: {1,2}
%e A325796     8: {1,1,1}
%e A325796    10: {1,3}
%e A325796    12: {1,1,2}
%e A325796    16: {1,1,1,1}
%e A325796    18: {1,2,2}
%e A325796    20: {1,1,3}
%e A325796    24: {1,1,1,2}
%e A325796    28: {1,1,4}
%e A325796    30: {1,2,3}
%e A325796    32: {1,1,1,1,1}
%e A325796    36: {1,1,2,2}
%e A325796    40: {1,1,1,3}
%e A325796    42: {1,2,4}
%e A325796    48: {1,1,1,1,2}
%e A325796    54: {1,2,2,2}
%t A325796 Select[Range[100],DivisorSigma[0,#]>=Total[Cases[FactorInteger[#],{p_,k_}:>PrimePi[p]*k]]&]
%Y A325796 Positions of nonnegative terms in A325794.
%Y A325796 Heinz numbers of the partitions counted by A325832.
%Y A325796 Cf. A000005, A002033, A056239, A112798, A299702.
%Y A325796 Cf. A325694, A325780, A325781, A325792, A325793, A325795, A325797, A325798.
%K A325796 nonn
%O A325796 1,2
%A A325796 _Gus Wiseman_, May 23 2019