A306720 Even numbers that are not the sum of two unitary abundant numbers (not necessarily distinct).

2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 62, 64, 66, 68, 70, 74, 76, 78, 80, 82, 86, 88, 90, 92, 94, 98, 102, 104, 106, 110, 114, 116, 118, 122, 124, 126, 128, 130, 134, 138, 142, 146, 150

Offset: 1

Author

Amiram Eldar, Mar 06 2019

Keywords

• nonn
• fini
• full

Comments

The unitary version of A048242.

a(6066) = 530086 is the last term. te Riele proved that every even number larger than 530086 is the sum of two unitary abundant numbers (not necessarily distinct). The corresponding sequence of odd numbers is also finite, but he did not calculate the last term, and only showed that it is below 2004452254833.

Examples

			Since the unitary abundant numbers begin with 30, 42, 66, 70, ... the first integers which are missing from this sequence are 60 = 30 + 30, 72 = 30 +42, 84 = 42 + 42, 96 = 30 + 66, 100 = 30 + 70, ...
		

Links

• Amiram Eldar, Table of n, a(n) for n = 1..6066
• Herman J. J. te Riele, On the representation of the positive integers as the sum of two unitary abundant numbers, Stichting Mathematisch Centrum, Numerieke Wiskunde NW 19/75 (1975).

Crossrefs

Cf. A034683, A048242.