A231093 Initial members of abundant octuplets, i.e., values of n such that (n, n+2, n+4, n+6, n+8, n+10, n+12, n+14) are all abundant numbers.

221355126, 402640540, 668862580, 739577140, 1415514246, 1598558646, 1678915540, 1714512246, 1812156340, 1829740086, 1892686326, 2097915966, 2259080046, 2452774780, 2453605540, 2521418740, 2726361940, 3118553740, 3252749646, 3318076446, 4119153340, 4748101660

Offset: 1

Author

Shyam Sunder Gupta, Nov 03 2013

Keywords

• nonn

Examples

			221355126, 221355128, 221355130, 221355132, 221355134, 221355136, 221355138, 221355140 are abundant, thus the smallest number is listed.
		

Links

• Donovan Johnson, Table of n, a(n) for n = 1..500

Crossrefs

Cf. A005101, A108926, A231086, A231088, A231089, A231090, A231092.

Programs

Mathematica

 AbundantQ[n_] := DivisorSigma[1, n] > 2n; m = 0; a = {}; Do[If[AbundantQ[n], m = m + 1; If[m > 7, AppendTo[a, n - 14]], m = 0], {n, 2, 2000000000, 2}];a