The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A325407 Nonprime Heinz numbers of multiples of triangular partitions, or of finite arithmetic progressions with offset 0. 11
 1, 6, 21, 30, 65, 133, 210, 273, 319, 481, 731, 1007, 1403, 1495, 2059, 2310, 2449, 3293, 4141, 4601, 4921, 5187, 5311, 6943, 8201, 9211, 10921, 12283, 13213, 14993, 15247, 16517, 19847, 22213, 24139, 25853, 28141, 29341, 29539, 30030, 31753, 37211, 40741 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The Heinz number of an integer partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k), so these are numbers of the form Product_{k = 1...b} prime(k * c) for some b > 1 and c > 0. LINKS EXAMPLE The sequence of terms together with their prime indices begins: 1: {} 6: {1,2} 21: {2,4} 30: {1,2,3} 65: {3,6} 133: {4,8} 210: {1,2,3,4} 273: {2,4,6} 319: {5,10} 481: {6,12} 731: {7,14} 1007: {8,16} 1403: {9,18} 1495: {3,6,9} 2059: {10,20} 2310: {1,2,3,4,5} 2449: {11,22} 3293: {12,24} 4141: {13,26} 4601: {14,28} MATHEMATICA primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]]; Select[Range[10000], !PrimeQ[#]&&SameQ@@Differences[Prepend[primeMS[#], 0]]&] CROSSREFS Cf. A007294, A007862, A049988, A056239, A112798, A325327, A325328, A325355, A325359, A325367, A325390. Sequence in context: A347875 A287165 A280296 * A239920 A173622 A302868 Adjacent sequences: A325404 A325405 A325406 * A325408 A325409 A325410 KEYWORD nonn AUTHOR Gus Wiseman, May 03 2019 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified March 22 22:37 EDT 2023. Contains 361434 sequences. (Running on oeis4.)