A367187 Numbers which are the sum of a prime number and a Fibonacci number of index >1 in at least two ways.
4, 5, 6, 7, 8, 10, 12, 13, 14, 15, 16, 18, 19, 20, 21, 22, 24, 25, 26, 28, 30, 31, 32, 34, 36, 37, 38, 39, 40, 42, 44, 45, 46, 48, 49, 50, 51, 52, 54, 55, 56, 57, 58, 60, 61, 62, 63, 64, 66, 68, 69, 72, 74, 75, 76, 78, 80, 81, 82, 84, 86, 87, 88, 91, 92, 94, 96, 98, 100
Offset: 1
Keywords
Examples
4 is a term since 4 = 1+3 = 2+2. 5 is a term since 5 = 2+3 = 3+2. 57 is a term since 57 = 2+55 = 23+34.
Programs
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PARI
isfib(n) = if (n>0, my(k=n^2); k+=(k+1)<<2; issquare(k) || issquare(k-8)); isok(k) = sum(i=1, primepi(k), isfib(k-prime(i))) > 1; \\ Michel Marcus, Nov 09 2023