A062306 Number of ways writing 2^n as a sum of two nonprime numbers.
1, 0, 1, 4, 7, 19, 36, 82, 170, 362, 740, 1537, 3144, 6443, 13116, 26661, 54034, 109386, 221121, 446502, 900436, 1814910, 3655069, 7356483, 14796994, 29750473, 59789057, 120112121, 241218391, 484287995, 972034297, 1950544851, 3913243144, 7849331541, 15741697002
Offset: 1
Keywords
Examples
For n = 5: 2^5 = 32 = 4+28 = 6+26 = 8+24 = 10+22 = 12+20 = 14+18 = 16+16, so a(5) = 7.
Links
- Amiram Eldar, Table of n, a(n) for n = 1..40
Formula
a(n) = A062610(2^n) = number of nonprime+nonprime partitions of 2^n.
Extensions
More terms from Dean Hickerson, Jul 23 2001
a(28)-a(32) from Sean A. Irvine, Mar 25 2023
a(33)-a(35) from Amiram Eldar, Jul 17 2024