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 A238744 #13 May 15 2022 11:40:05 %S A238744 1,1,1,1,1,2,1,1,1,1,1,1,2,1,2,1,1,2,2,1,1,1,1,1,2,1,1,2,1,2,2,1,2,1, %T A238744 1,1,1,2,1,1,1,2,1,1,3,1,1,1,1,1,1,2,2,2,2,2,1,2,2,2,1,1,1,3,1,2,1,2, %U A238744 1,2,1,2,1,1,1,1,1,2,1,2,2,1,1,2,1,1,2 %N A238744 Irregular table read by rows: T (n, k) gives the number of primes p such that p^k divides n; table omits all zero values. %C A238744 If the prime signature of n (nonincreasing version) is viewed as a partition, row n gives the conjugate partition. %F A238744 Row n is identical to row A124859(n) of table A212171. %e A238744 24 = 2^3*3 is divisible by two prime numbers (2 and 3), one square of a prime (4 = 2^2), and one cube of a prime (8 = 2^3); therefore, row 24 of the table is {2,1,1}. %e A238744 From _Gus Wiseman_, Mar 31 2022: (Start) %e A238744 Rows begin: %e A238744 1: () 16: (1,1,1,1) 31: (1) %e A238744 2: (1) 17: (1) 32: (1,1,1,1,1) %e A238744 3: (1) 18: (2,1) 33: (2) %e A238744 4: (1,1) 19: (1) 34: (2) %e A238744 5: (1) 20: (2,1) 35: (2) %e A238744 6: (2) 21: (2) 36: (2,2) %e A238744 7: (1) 22: (2) 37: (1) %e A238744 8: (1,1,1) 23: (1) 38: (2) %e A238744 9: (1,1) 24: (2,1,1) 39: (2) %e A238744 10: (2) 25: (1,1) 40: (2,1,1) %e A238744 11: (1) 26: (2) 41: (1) %e A238744 12: (2,1) 27: (1,1,1) 42: (3) %e A238744 13: (1) 28: (2,1) 43: (1) %e A238744 14: (2) 29: (1) 44: (2,1) %e A238744 15: (2) 30: (3) 45: (2,1) %e A238744 (End) %t A238744 Table[Length/@Table[Select[Last/@FactorInteger[n],#>=k&],{k,Max@@Last/@FactorInteger[n]}],{n,2,100}] (* _Gus Wiseman_, Mar 31 2022 *) %Y A238744 Row lengths are A051903(n); row sums are A001222(n). %Y A238744 Cf. A217171. %Y A238744 These partitions are ranked by A238745. %Y A238744 For prime indices A296150 instead of exponents we get A321649, rev A321650. %Y A238744 A000700 counts self-conjugate partitions, ranked by A088902. %Y A238744 A003963 gives product of prime indices, conjugate A329382. %Y A238744 A008480 gives number of permutations of prime indices, conjugate A321648. %Y A238744 A056239 adds up prime indices, row sums of A112798. %Y A238744 A124010 gives prime signature, sorted A118914, length A001221. %Y A238744 A352486-A352490 are sets related to the fixed points of A122111. %Y A238744 Cf. A000701, A000720, A046682, A238747, A258116, A319005, A330644, A352491. %K A238744 nonn,tabf %O A238744 2,6 %A A238744 _Matthew Vandermast_, Apr 28 2014