A076429 Sum of numbers that cannot be written as t*p(n) + u*p(n+1) for nonnegative integers t, u, where p(n) is the n-th prime.
1, 14, 114, 675, 2610, 6576, 14616, 27423, 65758, 121590, 200250, 354600, 481740, 636111, 972946, 1543438, 2052330, 2654850, 3609375, 4292820, 5326308, 6902883, 8780068, 12023616, 15516000, 17510850, 19669731, 22045986, 24606288
Offset: 1
Keywords
References
- Fred. Schuh, Vragen betreffende een onbepaalde vergelijking, Nieuw Tijdschrift voor Wiskunde, 52 (1964-1965) 193-198.
Programs
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Maple
seq((ithprime(n)-1)*(ithprime(n+1)-1)*(2*ithprime(n)*ithprime(n+1)-ithprime(n)-ithprime(n+1)-1)/12,n=1..40);
Formula
a(n) = (p(n)-1) * (p(n+1)-1) * (2*p(n)*p(n+1)-p(n)-p(n+1)-1) / 12.